Articles

Find answers to your health-related questions in our Ilustrated Health Encyclopedia

  • Disease

    Macroamylasemia

    Macroamylasemia is the presence of an abnormal substance called macroamylase in the blood.

  • Disease

    Macroglobulinemia of Waldenstrom

    Lymphocytoid appearing plasma cell nucleus similar to a lymphocyte and cytoplasm similar to a plasma cell.

    Macroglobulinemia of Waldenstrom is a cancer of the B lymphocytes (a type of white blood cell). It is associated with the overproduction of proteins called IgM .

  • Special Topic

    Macroglossia

    Structures of the throat include the esophagus, trachea, epiglottis and tonsils.

    Macroglossia is a disorder in which the tongue is larger than normal.

  • Special Topic

    Macrosomia

    Macrosomia is the condition of having an unusually large body. The body is in proportion, with the extremities and head also enlarged. Disorders that include this condition are gigantism and acromegaly.

    Macrosomia describes an unusually large body size. It is often used to describe an oversized fetus.

  • Special Topic

    Macula lutea

    The macula is the yellow oval spot at the center of the retina (back of the eye) that contains blood vessels and nerve fibers.

    The macula lutea is the yellow oval spot at the center of the (back of the eye). It is responsible for sharp, detailed central vision (also called visual acuity).

  • Disease

    Macular degeneration - age-related

    Macular degeneration is a disease of the retina that affects the macula in the back of the eye. The macula is important for clear central vision, allowing an individual to see fine details. There are two types of macular degeneration, dry and wet. Dry macular degeneration is more common and is characterized by the thinning of the retina and drusen, small yellowish-white deposits that form within the retina. The dry form of macular degeneration is usually mild. Wet macular degeneration can happen more quickly and be more serious. It occurs when vessels under the retinal layer hemorrhage and cause the retinal cells to die creating blind spots or distorted vision in the central vision. The disease becomes increasingly common amongst people in each succeeding decade over 50.

    Macular degeneration is an eye disorder that slowly destroys sharp, central vision. This makes it difficult to see fine details and read. The disease is most common in people over age 60, which is why it is often called age-related macular degeneration (ARMD, or AMD).

  • Symptoms

    Macule

    The skin is the largest organ of the body.  The skin and its derivatives (hair, nails, sweat and oil glands) make up the integumentary system. One of the main functions of the skin is protection.  It protects the body from external factors such as bacteria, chemicals, and temperature.  The skin contains secretions that can kill bacteria and the pigment melanin provides a chemical pigment defense against ultraviolet light that can damage skin cells.  Another important function of the skin is body temperature regulation. When the skin is exposed to a cold temperature, the blood vessels in the dermis constrict. This allows the blood which is warm, to bypass the skin.  The skin then becomes the temperature of the cold it is exposed to.  Body heat is conserved since the blood vessels are not diverting heat to the skin anymore.  Among its many functions the skin is an incredible organ always protecting the body from external agents.

    A macule is a flat, distinct, discolored area of skin that is usually less than 1 centimeter wide. It usually does not include a change in skin texture or thickness.

  • Nutrition

    Magnesium in diet

    Magnesium is an essential mineral for human nutrition.

  • Test

    Magnetic resonance angiography

    Magnetic resonance angiography is an exam of the blood vessels. Unlike traditional that involves placing a tube (catheter) into the body, MRA is noninvasive.

  • Maindex

  • Maindex

  • Disease

    Major depression

    Depression is defined as a mood disorder, and there are several subtypes. Bipolar disorder, also known as manic-depressive illness, is considered in a separate category.

    Depression may be described as feeling sad, blue, unhappy, miserable, or down in the dumps. Most of us feel this way at one time or another for short periods. True clinical depression is an illness. It is a mood disorder in which feelings of sadness, loss, anger, or frustration interfere with daily ...

  • Disease

    Major depression with psychotic features

    Depression is defined as a mood disorder, and there are several subtypes. Bipolar disorder, also known as manic-depressive illness, is considered in a separate category.

    Major depression with psychotic features is a mental disorder in which a person has depression along with loss of touch with reality (psychosis). See also:

  • Self-Care Instructions

    Make peak flow a habit!

  • Self-Care Instructions

    Making everyday tasks easier - arthritis

  • Disease

    Malabsorption

    The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.

    Malabsorption is difficulty absorbing nutrients from food.

  • Symptoms

    Malaise

    Malaise is a generalized feeling of discomfort, illness, or lack of well-being.

  • Disease

    Malaria

    Malaria is a disease caused by parasites that are carried by mosquitoes. Once in the bloodstream, the parasite inhabits the red blood cell (RBC).  This picture shows purple-stained malaria parasites inside red blood cells.

    Malaria is a parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia.

  • Poison

    Malathion poisoning

    Malathion is a type of insecticide, a product used to kill or control bugs. Poisoning may occur if you swallow malathion, handle the product without gloves, or fail to wash hands soon after exposure. Significant amounts are absorbed through the skin unless proper precautions are taken. This is for ...

  • Disease

    Male pattern baldness

    Male pattern baldness is a sex-linked characteristic that is passed from mother to child. A man can more accurately predict his chances of developing male pattern baldness by observing his mother's father than by looking at his own father.

    Male pattern baldness is the most common type of hair loss in men.

  • Special Topic

    Malignancy

    Malignancy refers to cells that are cancerous. Malignant cells may spread from their primary cancer source. This is called metastatic cancer.

    The term “malignancy” refers to cancerous cells that have the ability to spread to other sites in the body (metastasize) or to invade and destroy tissues. Malignant cells tend to have fast, uncontrolled growth due to changes in their genetic makeup. Malignant cells that are resistant to ...

  • Disease

    Malignant hypertension

    The kidneys filter wastes and excrete fluid when the pressure of blood in the bloodstream forces blood through the internal structures of the kidney.

    Malignant hypertension is very that comes on suddenly and quickly. The lower (diastolic) blood pressure reading, which is normally around 80 mmHg, is often above 130 mmHg.

  • Disease

    Malignant hyperthermia

    Malignant hyperthermia is disease passed down through families that causes a fast rise in body temperature () and severe muscle contractions when the affected person gets . This condition is not the same as hyperthermia that is due to medical emergencies such as or infection.

  • Disease

    Malignant otitis externa

    Ear anatomy

    Malignant otitis externa is a disorder involving infection and damage of the bones of the ear canal and at the base of the skull.

  • Disease

    Malignant teratoma

    This MRI scan shows a tumor (teratoma) at the base of the spine (seen on the left lower edge of the screen), located in the sacrum and coccyx (sacrococcygeal) area. Teratomas are present at birth and may contain hair, teeth, and other tissues.

    Malignant teratoma is a type of cancer made of that contain one or more of the three layers of cells found in a developing baby (embryo). These layers are called ectoderms, mesoderms, and endoderms.

  • Self-Care Instructions

    Mallet finger - aftercare

    Baseball finger; Drop finger; Avulsion fracture – mallet finger

  • Disease

    Mallory-Weiss tear

    The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.

    A Mallory-Weiss tear occurs in the of the lower part of the esophagus or upper part of the stomach, near where they join. The tear may bleed.

  • Disease

    Malnutrition

    The U.S. Department of Agriculture's newest food guide, called MyPlate, encourages consumers to make healthier food choices. The guide encourages you to eat less and avoid oversized portions. Half your plate should be filled with fruits and vegetables. At least half of your grains should be whole grains. You also should switch to fat-free or low-fat milk.

    Malnutrition is the condition that occurs when your body does not get enough nutrients.

  • Disease

    Malocclusion of teeth

    Prognathism is a descriptive term for a jaw (lower or upper) that protrudes forward beyond the plane of the face.

    Malocclusion means the teeth are not aligned properly.

  • Special Topic

    Mammogram - calcifications

    Mammogram

    Calcifications are tiny deposits of calcium in your breast tissue. They are often seen on a .

  • Test

    Mammography

    The female breast is either of two mammary glands (organs of milk secretion) on the chest.

    A mammogram is an picture of the breasts. It is used to find breast tumors and cancer.

  • imagepage

    Manage your blood sugar

    Checking your blood sugar levels often and writing down the results will tell you how well you are managing your diabetes so you can stay as healthy as possible. The best times to check your blood sugar are before meals and at bedtime. Your blood sugar meter may have computer software to help you ...

  • Self-Care Instructions

    Managing latex allergies at home

    Latex products; Latex allergy; Latex sensitivity

  • Self-Care Instructions

    Managing menopause at home

    Perimenopause – self-care; Hormone replacement therapy – self-care; HRT- self-care

  • Self-Care Instructions

    Managing migraines at home

  • Self-Care Instructions

    Managing pain during labor

  • Self-Care Instructions

    Managing tension headaches at home

    The most common cause of tension-type headaches is muscle contraction in the head, neck or shoulders.

  • Self-Care Instructions

    Managing your blood sugar

    Hyperglycemia – control; Hypoglycemia – control; Diabetes – blood sugar control

  • Self-Care Instructions

    Managing your chronic pain

  • Self-Care Instructions

    Managing your depression - teens

    Recognizing depression in your teen; Helping your teen with depression

  • Self-Care Instructions

    Managing your weight gain during pregnancy

  • Self-Care Instructions

    Managing your weight with healthy eating

    Protein is an important nutrient that builds muscles and bones and provides energy. Protein can help with weight control because it helps you feel full and satisfied from your meals.The healthiest proteins are the leanest. This means that they have the least fat and calories. The best protein choices are fish or shellfish, skinless chicken or turkey, low-fat or fat-free dairy (skim milk, low-fat cheese), and egg whites or egg substitute. The best red meats are the leanest cuts (loin and tenderloin). Other healthy options are beans, legumes (lentils and peanut butter), and soy foods such as tofu or soymilk.

  • Disease

    Maple syrup urine disease

    Maple syrup urine disease (MSUD) is a disorder passed down through families in which the body cannot break down certain parts of proteins. Urine in persons with this condition can smell like maple syrup.

  • Disease

    Marfan syndrome

    Pectus excavatum is a condition in which the "breast bone" (sternum) appears sunken and the chest concave.  It is sometimes called  "funnel chest".  The majority of these cases are not associated with any other condition (isolated findings).  However, some syndromes include pectus excavatum.

    Marfan syndrome is a disorder of connective tissue, the tissue that strengthens the body’s structures. Disorders of connective tissue affect the skeletal system, cardiovascular system, eyes, and skin.

  • Disease

    Marijuana intoxication

    (“pot”) intoxication is the euphoria, relaxation, and sometimes undesirable side effects that can occur when people use marijuana. Marijuana is the most commonly used illegal drug in the United States. The drug is usually smoked, but is sometimes eaten.

  • Injury

    Marine animal stings or bites

    Symptoms of a marine animal sting can include pain, burning, swelling, redness, and bleeding. To treat a sting, keep the victim very still and wipe off stingers or tentacles with a towel or sand being careful to avoid contact with the tentacles or stingers. Wash the area with salt water. In some cases soaking the wound in very warm water is recommended.

    Marine animal stings or bites refer to poisonous bites or stings from any form of sea life, including jellyfish.

  • Surgery

    Mastectomy

    The female breast is either of two mammary glands (organs of milk secretion) on the chest.

    A mastectomy is surgery to remove the entire breast, including the skin and nipple. It is usually done to treat .

  • Questions To Ask Your Doctor

    Mastectomy and breast reconstruction - what to ask your doctor

    You may be having a mastectomy. This is surgery to remove your breast. Most often, a mastectomy is done to treat . Sometimes it is done to prevent cancer in women who have a high risk of getting breast cancer in the future. You may also have breast reconstruction. This is surgery to create a new ...

  • Surgery

    Mastoidectomy

    A mastoidectomy is surgery to remove cells in the hollow, air-filled spaces in the skull behind the ear. These cells are called mastoid air cells.

  • Disease

    Mastoiditis

    Mastoiditis is an infection of the bony air cells in the mastoid bone, located just behind the ear.  It is rarely seen today because of the use of antibiotics to treat ear infections.  This child has drainage from the ear and redness (erythema) behind the ear over the mastoid bone.

    Mastoiditis is an infection of the mastoid bone of the skull. The mastoid is located just behind the ear.

  • Disease

    Mathematics disorder

    Mathematics disorder is a condition in which a child’s math ability is far below normal for their age, intelligence, and education.

  • Special Topic

    Maximizing your teaching moment

  • Disease

    McArdle syndrome

    McArdle syndrome is the inability to break down glycogen. Glycogen is an important source of energy that is stored in all tissues, but especially in the muscles and liver.

  • Disease

    McCune-Albright syndrome

    
The skeleton is made up of 206 bones in the adult and contributes to the form and shape of the body. The skeleton has several important functions for the body. The bones of the skeleton provide support for the soft tissues. For example, the rib cage supports the thoracic wall. Most muscles of the body are attached to bones which act as levers to allow movement of body parts. The bones of the skeleton also serve as a reservoir for minerals, such as calcium and phosphate. Finally, most of the blood cell formation takes places within the marrow of certain bones.

    McCune-Albright syndrome is a genetic disease that affects the bones and color (pigmentation) of the skin.

  • Disease

    Measles

    Koplik spots are seen with measles. They are small, white spots (often on a reddened background) that occur on the inside of the cheeks early in the course of measles.

    Measles is a very contagious (easily spread) illness caused by a virus.

  • Disease

    Meatal stenosis

    The female and male urinary tracts are relatively the same except for the length of the urethra.

    Meatal stenosis is a narrowing of the opening of the urethra, the tube through which urine leaves the body.

  • Special Topic

    Mechanical ventilator - infants

    A mechanical ventilator is a machine that assists with breathing. This article discusses the use of mechanical ventilators in infants. WHY IS A MECHANICAL VENTILATOR USED? A ventilator is used to provide breathing support for ill or immature babies. Sick or babies are often too weak, sick, or ...

  • Disease

    Meckel's diverticulum

    The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.

    A Meckel’s diverticulum is a pouch on the wall of the lower part of the intestine that is present at birth (congenital). The diverticulum may contain tissue that is the same as tissue of the stomach or pancreas.

  • Surgery

    Meckel’s diverticulectomy

    Meckel’s diverticulectomy is surgery to remove an abnormal pouch on the lining of the small intestine (bowel). This pouch is called a .

  • Poison

    Meclofenamate overdose

    Meclofenamate (Meclomen) is a nonsteroidal anti-inflammatory drug (NSAID) used to treat arthritis. Meclofenamate occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this medication. This is for information only and not for use in the treatment or ...

  • Disease

    Meconium aspiration syndrome

    Meconium aspiration syndrome is a serious condition in which a newborn breathes a mixture of meconium and amniotic fluid into the lungs around the time of delivery.

  • Special Topic

    Medial

    There are three body views (front, back and side) that may be helpful if you are uncertain of a body area. Many areas are referred to by both descriptive and technical names. For example, the back of the knee is called the popliteal fossa. However, areas like the "flank" may not have both names, so the location may be unclear.

    Medial means toward the middle or center. It is the opposite of . The term is used to describe general positions of body parts. For example, the chest is medial to the arm. Your health care provider may use this term to clearly explain the relationship between things found during a physical exam or ...

  • Injury

    Medial collateral ligament (MCL) injury of the knee

    Initial treatment of an MCL injury includes ice to the area, elevation of the joint above the level of the heart, non-steroidal anti-inflammatory drugs (NSAIDs), and limited physical activity until the pain and swelling subside. A hinged knee immobilizer should be used to protect the ligament as it heals. The extent of this type of injury is usually excessive stretching of the ligament causing the pain and tenderness.

    Medial collateral ligament (MCL) injury is an injury to the ligament on the inner part of the knee. This ligament keeps your shin bone (tibia) in place. It can be a stretch, partial tear, or complete tear of the ligament.

  • Disease

    Mediastinal tumor

    The major features of the lungs include the bronchi, the bronchioles and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.

    Mediastinal tumors are growths that form in the middle of the chest area, which separates the lungs.

  • Disease

    Mediastinitis

    Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.

    Mediastinitis is swelling and irritation (inflammation) of the area between the lungs (mediastinum). This area contains the heart, large blood vessels, windpipe (trachea), esophagus, thymus gland, lymph nodes, and connective tissues.

  • Test

    Mediastinoscopy with biopsy

    Mediastinoscopy is a procedure in which a lighted instrument (mediastinoscope) is inserted through a neck incision to visually examine the structures in the top of the chest cavity and take tissue samples. This procedure can be used to biopsy lymph nodes surrounding the airway to help diagnose or see how far a particular disease has spread.

    Mediastinoscopy with is a procedure in which a lighted instrument (mediastinoscope) is inserted in the space in the chest between the lungs (mediastinum), and tissue is taken (biopsy) from any unusual growth or lymph nodes.

  • imagepage

    Medical alert bracelet

    People with diabetes should always wear a medical alert bracelet or necklace that emergency medical workers will be able to find. Medical identification products can help ensure proper treatment in an emergency.

  • Special Topic

    Medication safety during your hospital stay

    Five-rights; Medication administration; Medical errors – medication

  • Special Topic

    Medications for back pain

  • Self-Care Instructions

    Medications, injections, and supplements for arthritis

  • Special Topic

    Medicine safety and children

    Medication safety; Poison control

  • Self-Care Instructions

    Medicines for osteoporosis

    Alendronate (Fosamax); Ibandronate (Boniva); Risedronate (Actonel); Zoledronic acid (Reclast); Raloxifene (Evista); Teriparatide (Forteo); Low bone density – medicines; Osteoporosis – medicines

  • Self-Care Instructions

    Mediterranean diet

  • Disease

    Medullary carcinoma of thyroid

    This CT scan of the upper chest (thorax) shows a malignant thyroid tumor (cancer). The dark area around the trachea (marked by the white U-shaped tip of the respiratory tube) is an area where normal tissue has been eroded and died (necrosis) as a result of tumor growth.

    Medullary carcinoma of the thyroid is cancer of the thyroid gland that starts in cells that release a hormone called calcitonin. Such cells are called “C” cells.

  • Disease

    Medullary cystic kidney disease

    The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and stimulating red blood cell production.

    Medullary cystic kidney disease (MCKD) is an inherited condition in which cysts in the center of each kidney cause the kidneys to gradually lose their ability to work.

  • Disease

    Meibomianitis

    The cornea is the clear layer covering the front of the eye. The cornea works with the lens of the eye to focus images on the retina.

    Meibomianitis is an inflammation of the meibomian glands, a group of oil-secreting (sebaceous) glands in the eyelids. These glands have tiny openings to release oils onto the surface of the cornea.

  • Special Topic

    Melanin

    Melanin is the natural substance that gives color (pigment) to hair, skin, and the iris.

  • Disease

    Melanoma

    Melanoma is a malignant skin tumor that involves the skin cells that produce pigment (melanin). The risk of melanoma increases with age, but frequently effects young, otherwise healthy people. Melanoma is an aggressive type of cancer that can spread very rapidly.

    Melanoma is the most dangerous type of skin cancer. It is the leading cause of death from skin disease. Melanoma can also involve the .

  • Disease

    Melanoma of the eye

    The retina is the internal layer of the eye that receives and transmits focused images. The retina is normally red due to its rich blood supply.

    Melanoma of the eye is cancer that occurs in various parts of the eye.

  • Disease

    Melasma

    Melasma is patches of dark skin that appear on areas of the face exposed to the sun.

  • Disease

    Membranoproliferative GN

    The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and stimulating red blood cell production.

    Membranoproliferative glomerulonephritis is a kidney disorder that involves inflammation and changes to kidney cells. It may lead to kidney problems.

  • Disease

    Membranous nephropathy

    The kidneys are responsible for removing wastes from the body, regulating electrolyte balance and blood pressure, and stimulating red blood cell production.

    Membranous nephropathy is a kidney disorder that leads to changes and inflammation of the structures inside the kidney that help filter wastes and fluids. The inflammation may lead to problems with kidney function.

  • Symptoms

    Memory loss

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Memory loss (amnesia) is unusual forgetfulness. You may not be able to remember new events, recall one or more memories of the past, or both.

  • Disease

    Meniere’s disease

    Ear anatomy

    Meniere’s disease is an inner ear disorder that affects balance and hearing. See also:

  • Disease

    Meningitis

    One of the physically demonstrable symptoms of meningitis is Brudzinski's sign. Severe neck stiffness causes a patient's hips and knees to flex when the neck is flexed.

    Meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges).

  • Disease

    Meningitis - cryptococcal

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Cryptococcal is a fungal infection of the tissues covering the brain and spinal cord (meninges).

  • Disease

    Meningitis - gram-negative

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Gram-negative is an infection of the membranes covering the brain and spinal cord (meninges) from bacteria that turn pink when exposed to a special stain (Gram-negative bacteria).

  • Disease

    Meningitis - H. influenzae

    This picture shows the organism Haemophilus influenza.  Infections caused by Haemophilus influenza usually occur in children under 6 years old and are extremely serious.  Haemophilus (type B) is responsible for meningitis, periorbital cellulitis, buccal cellulitis and epiglottitis, septic arthritis, osteomyelitis, pericarditis, and bacteremia.  The small organisms live within cells (intracellular) as shown in this picture.  (Image courtesy of the Centers for Disease Control and Prevention.)

    Haemophilus influenzae meningitis is a bacterial infection of the membranes covering the brain and spinal cord (meninges). See also: Aseptic meningitis

  • Disease

    Meningitis - meningococcal

    Meningococcemia is a life-threatening infection that occurs when the bacteria, Neisseria meningitidis, invades the blood stream.  Bleeding into the skin (petechiae and purpura) usually occurs and the tissue may die (become necrotic or gangrenous).  If the patient survives, the areas heal with scarring.

    Meningococcal meningitis is an infection that results in swelling and irritation (inflammation) of the membranes covering the brain and spinal cord.

  • Disease

    Meningitis - pneumococcal

    This picture shows the organism Pneumococci.  These bacteria are usually paired (diplococci) or appear in chains.  Pneumococci are typically associated with pneumonia, but may cause infection in other organs such as the brain (pneumococcal meningitis) and blood stream (pneumococcal septicemia).  (Image courtesy of the Centers for Disease Control and Prevention.)

    Pneumococcal meningitis is an infection that causes swelling and irritation (inflammation) of the membranes covering the brain and spinal cord (meninges). See also: Aseptic meningitis

  • Disease

    Meningitis - staphylococcal

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Staphylococcal is a bacterial infection of the thin tissues covering the brain and spinal cord (meninges). See also: Aseptic meningitis

  • Disease

    Meningitis - tuberculous

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Tuberculous meningitis is an infection of the tissues covering the brain and spinal cord (meninges).

  • Surgery

    Meningocele repair

    Meningocele repair (also known as myelomeningocele repair) is surgery to repair birth defects of the spine and spinal membranes. Meningocele and myelomeningocele are types of .

  • Disease

    Meningococcemia

    Meningococcemia is an and potentially life-threatening infection of the bloodstream. See also:

  • Surgery

    Meniscal allograft transplantation

    Meniscal allograft transplantation is a type of surgery in which a meniscus — a cartilage ring in the knee — is placed into your knee. The new meniscus is taken from a person who has died (cadaver) and donated his or her tissue.

  • Injury

    Meniscus tears

    Knee arthroscopy is surgery that is done to check for problems, using a tiny camera to see inside your knee. Other medical instruments may also be inserted to repair your knee.

    Meniscus tears refer to a tear in the shock-absorbing cartilage (meniscus) of the knee.

  • Disease

    Menkes syndrome

    Hypotonia is often a sign of abnormality in the case of a newborn or older infant, and may suggest the presence of central nervous system dysfunction, genetic disorders, or muscle disorders. Hypotonic infants rest with their elbows and knees loosely extended, while infants with normal tone tend to have flexed elbows and knees. Head control may be poor or absent in the floppy infant with the head falling to the side, backward or forward.

    Menkes syndrome is an in which cells in the body cannot absorb enough copper.

  • Disease

    Menopause

    Menopause is the transition in a woman's life when the ovaries stop releasing eggs, menstrual activity decreases and eventually ceases, and the body decreases the production of the female hormones estrogen and progesterone.

    Menopause is time in a woman’s life when her periods (menstruation) eventually stop and the body goes through changes that no longer allow her to get pregnant. It is a natural event that normally occurs in women age 45 – 55.Menopause is a natural part of a woman’s aging process.The ...

  • Test

    Mental status testing

    Mental status testing is done to check your thinking ability, and to determine if any problems are getting better or worse. It is also called neurocognitive testing.

  • Poison

    Menthol overdose

    Menthol is used as a flavoring agent for candy and other products. This article discusses menthol poisoning from swallowing pure menthol. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local ...

  • Poison

    Meperidine hydrochloride overdose

    Meperidine hydrochloride is a painkiller. Meperidine hydrochloride occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this medication. This is for information only and not for use in the treatment or management of an actual poison exposure. If you ...

  • Poison

    Meprobamate overdose

    Meprobamate is a drug used to treat anxiety. Meprobamate occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this medication. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an ...

  • Poison

    Merbromin overdose

    Mebromin is a germ-killing (antiseptic) liquid. Mebromin occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this substance. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an ...

  • Poison

    Mercuric chloride poisoning

    Mercuric chloride is a very poisonous form of mercury. It is a type of mercury salt. There are different types of . This article discusses poisoning from swallowing mercuric chloride. This is for information only and not for use in the treatment or management of an actual poison exposure. If you ...

  • Poison

    Mercuric oxide poisoning

    Mercuric oxide is a form of mercury. It is a type of mercury salt. There are different types of . This article discusses poisoning from swallowing mercuric oxide. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you ...

  • Poison

    Mercury

    This article discusses poisoning from mercury. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or a local poison control center at 1-800-222-1222.

  • Poison

    Merthiolate poisoning

    Merthiolate is a mercury-containing substance that was once widely used as germ-killer and a preservative in many different products, including vaccines. Merthiolate poisoning occurs when large amounts of the substance are swallowed or come in contact with your skin. Poisoning may also occur if you ...

  • Test

    Mesenteric angiography

    Mesenteric arteriography is an examination of the abdominal vessels by using an injection of a contrast medium to help visualize the structures.  The test is performed after an endoscopy proves to be inconclusive and cannot locate the source of bleeding in the intestinal system, or other studies prove inadequate in evaluating abnormal growths. It may also be used to evaluate vessel damage after an abdominal trauma.

    Mesenteric angiography is a test used to examine the blood vessels that supply the small and large intestines. Angiography is an imaging test that uses x-rays and a special dye to see inside the arteries. Arteries are blood vessels that carry blood away from the heart.

  • Disease

    Mesenteric artery ischemia

    Mesenteric artery ischemia occurs when there is a narrowing or blockage of one or more of the three mesenteric arteries, the major arteries that supply the small and large intestines.

  • Disease

    Mesenteric venous thrombosis

    Mesenteric venous thrombosis is a in one or more of the major veins that drain blood from the intestine.

  • Disease

    Mesothelioma - benign-fibrous

    Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.

    Benign mesothelioma is a noncancerous of the lining of the lung and chest cavity, an area called the pleura. It is also called solitary fibrous tumor of the pleura. See also:

  • Disease

    Mesothelioma - malignant

    Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.

    Malignant mesothelioma is an uncommon cancerous of the lining of the lung and chest cavity (pleura) or lining of the abdomen (peritoneum) that is typically due to long-term asbestos exposure.

  • Disease

    Metabolic acidosis

    Insulin is a hormone produced by the pancreas that is necessary for cells to be able to use blood sugar.

    Metabolic acidosis is a condition in which there is too much acid in the body fluids.

  • Disease

    Metabolic neuropathies

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Metabolic neuropathies are nerve disorders that occur with diseases that disrupt the chemical processes in the body. See also: ;

  • Disease

    Metabolic syndrome

    Metabolic syndrome is a name for a group of risk factors that occur together and increase the risk for , , and .

  • Special Topic

    Metabolism

    Metabolism is the physical and chemical processes within the body related to body functions.

    Metabolism refers to all the physical and chemical processes in the body that convert or use energy, such as: Breathing Circulating blood Controlling body temperature Contracting muscles Digesting food and nutrients Eliminating waste through urine and feces Functioning of the brain and nerves

  • Special Topic

    Metabolite

    A metabolite is any substance produced or used during metabolism (digestion). In drug use, a metabolite usually refers to the end-product (what is remaining after metabolism).

    A metabolite is any substance produced during (digestion or other bodily chemical processes). The term metabolite may also refer to the product that remains after a drug is broken down (metabolized) by the body.

  • Disease

    Metachromatic leukodystrophy

    Metachromatic leukodystrophy (MLD) is a genetic disorder that affects nerves, muscles, other organs, and behavior. It slowly gets worse over time.

  • Poison

    Metal cleaner poisoning

    Metal cleaners are very strong chemical products that contain acids. This article discusses poisoning from swallowing or breathing in such products. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your ...

  • Poison

    Metal polish poisoning

    Metal polishes are used to clean all metals, brass, copper, or silver. This article discusses the harmful effects from swallowing metal polish. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your ...

  • Special Topic

    Metastasis

    A CT scan of the middle abdomen showing metastasis (cancer that has spread) in the left kidney in a patient with carcinoma of the lung.  Note the large dark circular tumor in the kidney on the right side of the picture.

    Metastasis is the movement or spreading of cancer cells from one organ or tissue to another. Cancer cells usually spread through the blood or the . If a cancer spreads, it is said to have “metastasized.”

  • Disease

    Metastatic brain tumor

    The major areas of the brain have one or more specific functions.

    A metastatic is cancer that started in another part of the body and spread to the brain.

  • Disease

    Metastatic cancer to the lung

    Bronchoscopy is a surgical technique for viewing the interior of the airways. Using sophisticated flexible fiber optic instruments, surgeons are able to explore the trachea, main stem bronchi, and some of the small bronchi. In children, this procedure may be used to remove foreign objects that have been inhaled. In adults, the procedure is most often used to take samples of (biopsy) suspicious lesions and for culturing specific areas in the lung.

    Metastatic cancer to the lung is cancer that starts somewhere else in the body and spreads to the lungs. See also:

  • Disease

    Metastatic pleural tumor

    The pleural membrane is the membrane lining the lung and the chest cavity.

    Metastatic pleural tumor is a type of that has spread from another organ to the thin membrane (pleura) surrounding the lungs.

  • Self-Care Instructions

    Metatarsal stress fractures - aftercare

    Broken foot bone; March fracture; March foot; Jone’s fracture

  • Disease

    Metatarsus adductus

    Metatarsus adductus is a foot deformity characterized by a sharp, inward angle of the front half of the foot. It is thought to occur as a result of the infant's position inside the uterus where the feet are bent inward at the instep. Most cases resolve spontaneously and the majority of the remainder can be corrected with simple exercises.

    Metatarsus adductus is a foot deformity. The bones in the front half of the foot bend or turn in toward the body.

  • Poison

    Methadone overdose

    Methadone is a very strong painkiller. It is also used to treat addiction. Methadone occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this medication. Methadone overdose can also occur if a person takes methadone with certain painkillers, such ...

  • Poison

    Methamphetamine overdose

    Methamphetamine is stimulant drug. A strong form of the drug is illegal sold on the streets. A much weaker form of the drug comes as a prescription for the treatment of narcolepsy. This article focuses on the illegal street drug. The street drug is usually a white crystal-like powder, called ...

  • Poison

    Methanol poisoning

    Methanol is a nondrinking type of alcohol used for industrial and automotive purposes. This article discusses poisoning from an overdose of methanol. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call ...

  • Test

    Methanol test

    Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.

    Methanol is a toxic type of alcohol used for industrial and automotive purposes. It is not found in alcoholic beverages. It is sometimes called “wood alcohol.” A test can be done to measure the amount of methanol in your blood. See also:

  • Poison

    Methapyrilene hydrochloride overdose

    Methapyrilene hydrochloride is an uncommon antihistamine found in cold or flu medicines. Methapyrilene hydrochloride overdose occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this medication. This is for information only and not for use in the ...

  • Disease

    Methemoglobinemia

    Blood is comprised of red blood cells, platelets, and various white blood cells.

    Methemoglobinemia is a blood disorder in which an abnormal amount of methemoglobin – a form of – is produced. Hemoglobin is the molecule in red blood cells that distributes oxygen to the body. Methemoglobin cannot release oxygen. In methemoglobinemia, the hemoglobin is unable to ...

  • Disease

    Methemoglobinemia - acquired

    Blood is comprised of red blood cells, platelets, and various white blood cells.

    Methemoglobinemia is a blood disorder in which the body cannot reuse after it is damaged. Hemoglobin is the oxygen-carrying molecule found in red blood cells. In some cases of methemoglobinemia, the hemoglobin is unable to effectively carry oxygen to body tissues. Acquired methemoglobinemia results ...

  • Poison

    Methyl salicylate overdose

    Methyl salicylate is a wintergreen-scented chemical found in many over-the-counter products, including muscle ache creams. Methyl salicylate occurs when someone accidentally or intentionally takes more than the normal or recommended amount of a product containing this substance. This is for ...

  • Test

    Methylene blue test

    The methylene blue test is a test to determine the type of (a blood disorder).

  • Test

    Methylmalonic acid test

    Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.

    Methylmalonic acid is a substance produced when proteins (called amino acids) in the body break down. A test can be done to measure the amount of methylmalonic acid in your blood.

  • Disease

    Methylmalonic acidemia

    Methylmalonic acidemia is a disorder, passed down through families, in which the body cannot break down certain proteins and fats. The result is a build up of a substance called methylmalonic acid in the blood. It is considered an inborn error of metabolism.

  • Disease

    Methylmercury poisoning

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Methylmercury poisoning is brain and nervous system damage from the chemical methylmercury.

  • Symptoms

    Metopic ridge

    A metopic ridge is a ridge of bone or suture line on the forehead between the two halves of the frontal bone. The ridging is caused when the two halves close prematurely.

    A metopic ridge is an abnormal shape of the skull. The ridge can be seen on the forehead.

  • Test

    MIBG scintiscan

    This image shows enlargement of the thyroid gland and extension down behind the breastbone (retrosternal space). The image, called a scintiscan, was generated using a radioactive isotope.

    An MIBG scintiscan is a type of imaging test. It uses a radioactive substance (called a tracer) and a special scanner to find or confirm the presence of and neuroblastoma. These are types of tumors that affect the nervous tissue.

  • Test

    Microalbuminuria test

    This test looks for a protein called albumin in a urine sample. See also:

  • Symptoms

    Microcephaly

    The "sutures" or anatomical lines where the bony plates of the skull join together can be easily felt in the newborn infant. The diamond shaped space on the top of the skull and the smaller space further to the back are often referred to as the "soft spot" in young infants.

    Microcephaly is a condition in which a person’s head is significantly smaller than normal for their age and sex, based on standardized charts. Head size is measured as the distance around the top of the head.

  • Symptoms

    Micrognathia

    The physical landmarks of the human face are very similar from one face to another.

    Micrognathia is a term for a lower jaw that is smaller than normal.

  • Disease

    Migraine

    One theory of the cause of migraine is a central nervous system (CNS) disorder. The CNS consists of the brain and spinal cord. In migraine, various stimuli may cause a series of neurologic and biochemical events which affect the brain's vascular system.

    A migraine is a common type of headache that may occur with symptoms such as nausea, vomiting, or sensitivity to light. In many people, a throbbing pain is felt only on one side of the head. Some people who get migraines have warning symptoms, called an aura, before the actual headache begins. An ...

  • Special Topic

    Migraine - resources

  • Poison

    Mildew remover poisoning

    Mildew removers are common household cleaners. Swallowing, breathing in the product, or spraying it in the eyes can be potentially dangerous. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local ...

  • Disease

    Milia

    Milia are tiny white bumps or small cysts on the skin. They are almost always seen in newborn babies.

  • Disease

    Milk-alkali syndrome

    Milk-alkali syndrome is an acquired condition in which there are high levels of calcium () and a shift in the body’s acid/base balance towards alkaline (metabolic ).

  • Poison

    Millipede toxin

    Millipedes are worm-like bugs called arthropods. Certain types of millipedes release a harmful substance (toxin) if they are threatened or if you handle them roughly. Millipedes can squirt toxin several inches that may cause allergic reactions in some people. This is for information only and not for ...

  • Poison

    Mineral oil overdose

    Mineral oil is a liquid oil produced from petroleum. Mineral oil overdose occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this substance. This is for information only and not for use in the treatment or management of an actual poison exposure. If ...

  • Poison

    Mineral spirits poisoning

    This article discusses the harmful effects from swallowing or breathing in mineral spirits. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the National ...

  • Disease

    Minimal change disease

    The urinary system is made up of the kidneys, ureters, urethra and bladder.

    Minimal change disease is a kidney disorder that can lead to , although the nephrons of the kidney look normal under a regular microscope.

  • Surgery

    Minimally invasive hip replacement

    Minimally invasive hip replacement is a technique used to perform hip replacement surgeries with a smaller surgical cut. Also, fewer muscles around the hip are cut or detached.

  • Self-Care Instructions

    Minor burns - aftercare

    Partial thickness burns

  • Disease

    Miscarriage

    A threatened miscarriage or spontaneous abortion occurs in approximately 10% of pregnancies between 7 and 12 weeks of gestation. Symptoms include vaginal bleeding, abdominal cramps, and low back pain.

    A miscarriage is the spontaneous loss of a fetus before the 20th week of pregnancy. (Pregnancy losses after the 20th week are called preterm deliveries.) A miscarriage may also be called a “spontaneous abortion.” This refers to naturally occurring events, not to medical abortions or ...

  • Disease

    Miscarriage - threatened

    A threatened miscarriage or spontaneous abortion occurs in approximately 10% of pregnancies between 7 and 12 weeks of gestation. Symptoms include vaginal bleeding, abdominal cramps, and low back pain.

    A threatened miscarriage is a condition that suggests a might take place before the 20th week of pregnancy.

  • Poison

    Mistletoe poisoning

    Mistletoe is an evergreen plant with white berries. Mistletoe poisoning occurs when someone eats any part of this plant. Poisoning can also occur if you drink tea created from the plant or its berries. This is for information only and not for use in the treatment or management of an actual poison ...

  • Disease

    Mitral stenosis

    Mitral stenosis is a heart valve disorder that narrows or obstructs the mitral valve opening. Narrowing of the mitral valve prevents the valve from opening properly and obstructs the blood flow from the left atrium to the left ventricle. This can reduce the amount of blood that flows forward to the body. The main risk factor for mitral stenosis is a history of rheumatic fever but it may also be triggered by pregnancy or other stress on the body such as a respiratory infection, endocarditis, and other cardiac disorders.

    The mitral valve separates the upper and lower chambers on the left side of the heart. Stenosis is a condition in which the valve does not open fully, restricting blood flow. Mitral stenosis is a disorder in which the mitral valve does not open fully.

  • Disease

    Mitral valve prolapse

    Mitral valve prolapse is a disorder in which, during the contraction phase of the heart, the mitral valve does not close properly. When the valve does not close properly it allows blood to backflow into the left atrium. Some symptoms can include palpitations, chest pain, difficulty breathing after exertion, fatigue, cough, and shortness of breath while lying down.

    Mitral valve prolapse is a heart problem in which the valve that separates the upper and lower chambers of the left side of the heart does not close properly.

  • Disease

    Mitral valve regurgitation

    Mitral regurgitation is a disorder in which the heart valve that separates the upper and lower chambers on the left side of the heart does not close properly. Regurgitation means leaking from a valve that does not close all the way.

  • Surgery

    Mitral valve surgery - minimally invasive

    Mitral valve surgery is surgery to either repair or replace the mitral valve in your heart. Blood that comes from the lungs enters the left atrium of the heart and crosses into the left ventricle. The mitral valve between these two chambers makes sure that the blood keeps moving forward. When the ...

  • Surgery

    Mitral valve surgery - open

    Mitral valve surgery is used to repair or replace the mitral valve in your heart. Blood flows between different chambers through valves that connect the chambers. One of these is the mitral valve. The mitral valve opens so blood can flow from the left atria to the left ventricle. The valve then ...

  • Disease

    Mittelschmerz

    The female reproductive organs are located in the lower abdomen.

    Mittelschmerz is one-sided, lower abdominal pain in women. It occurs at or around the time of an egg is released from the ovaries (ovulation).

  • Special Topic

    MMR vaccine

    Rubella is often called three-day measles.  Because of the very effective vaccine, rubella is seldom seen today.  The rubella vaccine is given in combination with measles (rubeola) and mumps.  (Image courtesy of the Centers for Disease Control and Prevention.)

    The MMR vaccine is a “3-in-1” vaccine that protects against , , and — all of which are potentially serious diseases of childhood.

  • Disease

    Molluscum contagiosum

    Molluscum is a viral infection which generally goes away by itself (is self-limited).  The lesions are typically raised, firm, flesh-colored bumps (papules) with a pearly or smooth shiny appearance.

    Molluscum contagiosum is a viral skin infection that causes raised, pearl-like or on the skin.

  • Disease

    Mongolian blue spots

    Mongolian blue spots are flat bluish- to bluish-gray skin markings commonly appearing at birth or shortly thereafter. They appear commonly at the base of the spine, on the buttocks and back and also can appear on the shoulders. Mongolian spots are benign and are not associated with any conditions or illnesses.

    Mongolian spots are flat, blue, or blue-gray skin markings near the buttocks that commonly appear at birth or shortly thereafter. See also:

  • Special Topic

    Monitoring your baby before labor

  • Disease

    Mononeuritis multiplex

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Mononeuritis multiplex is a nervous system disorder that involves damage to at least two separate nerve areas.

  • Disease

    Mononeuropathy

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Mononeuropathy is damage to a single nerve or nerve group, which results in , sensation, or other function of that nerve.

  • Disease

    Mononucleosis

    This so-called "Downy cell" is typical of lymphocytes infected by EBV (Epstein Barr Virus) or CMV (Cytomegalovirus) in infectious mononucleosis.  Downy cells may be classified as types I, II, or III. This is a type II Downy cell.

    Mononucleosis is a viral infection causing fever, sore throat, and swollen lymph glands, especially in the neck. See also: (acute CMV infection)

  • Test

    Mononucleosis spot test

    This so-called "Downy cell" is typical of lymphocytes infected by EBV (Epstein Barr Virus) or CMV (Cytomegalovirus) in infectious mononucleosis.  Downy cells may be classified as types I, II, or III. This is a type II Downy cell.

    The mononucleosis spot test looks for two in the blood that appear during or after an infection with the virus that causes mono or mononucleosis.

  • Symptoms

    Morning sickness

    Morning sickness usually begins during the first month of pregnancy and continues until the 14th to 16th week. Although, some women can have nausea and vomiting through their entire pregnancy. Morning sickness is very common and does not hurt the baby in any way.The exact cause of morning sickness is unknown. However, it may be caused by either hormonal changes or lower blood sugar during early pregnancy. Emotional stress, traveling, or some foods can aggravate the problem.

    Morning sickness is that can actually occur at any time of the day during pregnancy. See also:

  • Self-Care Instructions

    Morning sickness

  • Symptoms

    Moro reflex

    A newly born infant is also called a neonate.

    A reflex is a type of involuntary (without trying) response to stimulation. The Moro reflex is one of many reflexes that are seen at birth. It normally disappears after 3 or 4 months. See also:

  • Poison

    Morphine overdose

    Morphine is a very strong painkiller. Morphine overdose occurs when a person intentionally or accidentally takes too much of the medicine. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local ...

  • Disease

    Morquio syndrome

    Morquio syndrome is an inherited disease of metabolism in which the body is missing or doesn’t have enough of a substance needed to break down long chains of sugar molecules called glycosaminoglycans (formerly called mucopolysaccharides). The syndrome belongs to a group of diseases called ...

  • Disease

    Morton's neuroma

    Morton’s neuroma is an injury to the nerve between the toes, which causes thickening and pain. It commonly affects the nerve that travels between the third and fourth toes. See also:

  • Disease

    Mosaicism

    Mosaicism is a condition in which cells within the same person have a different genetic makeup. This condition can affect any type of cell, including: Blood cells Egg and sperm cells (gametes) Skin cells

  • Symptoms

    Mouth sores

    Hand-foot-and-mouth disease is a viral infection caused by Coxsackievirus that usually begins in the throat. Symptoms include; fever, sore throat, ulcers in the throat, headache, and a rash with blisters on the palms of the hands and soles of the feet.

    Different types of sores can appear anywhere in the mouth. Some of the places mouth sores can occur are: Bottom of the mouth Inner cheeks Gums Lips Tongue

  • Disease

    Mouth ulcers

    Oral thrush is characterized by ulcers or lesions in the mouth caused by the yeast fungus Candida albicans. The lesions are painful, slightly raised, whitish in appearance, and cause a dry mouth.

    Mouth are sores or open lesions in the mouth. See also:

  • Poison

    Mouthwash overdose

    Mouthwash occurs when someone accidentally or intentionally takes more than the normal or recommended amount of this substance. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency ...

  • Symptoms

    Movement - uncontrollable

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Uncontrollable movements include many types of movements that you cannot control. They can affect the arms, legs, face, neck, or other parts of the body. Examples of uncontrollable movements are: Loss of muscle tone (flaccidity) Slow, twisting, or continued movements (chorea, athetosis, or ...

  • Symptoms

    Movement - uncontrolled or slow

    Muscular atrophy is the decrease in size and wasting of muscle tissue.  Muscles that lose their nerve supply can atrophy and simply waste away.

    Uncontrolled or slow movement is a problem with muscle tone, usually in large muscle groups. The problem leads to slow, uncontrollable, jerky movements of the head, limbs, trunk, or neck.

  • Symptoms

    Movement - uncoordinated

    Muscular atrophy is the decrease in size and wasting of muscle tissue.  Muscles that lose their nerve supply can atrophy and simply waste away.

    Uncoordinated movement is due to a muscle control problem that causes an inability to coordinate movements. It leads to a jerky, unsteady, to-and-fro motion of the middle of the body (trunk) and an (walking style). It can also affect the limbs. The medical name of this condition is ataxia.

  • Symptoms

    Movement - unpredictable or jerky

    Jerky body movement is a condition in which a person makes fast movements that they cannot control and that have no purpose. These movements interrupt the person’s normal movement or posture. The medical name of this condition is chorea.

  • Self-Care Instructions

    Moving a patient from bed to a wheelchair

    Follow these steps to move a patient from bed to a wheelchair. The technique below assumes the patient can stand on at least one leg. If the patient cannot use his or her leg, you will need to use a lift to transfer the patient.

  • Test

    MRI

    MRI scans

    An MRI (magnetic resonance imaging) scan is an imaging test that uses powerful magnets and radio waves to create pictures of the body. It does not use radiation (x-rays). Single MRI images are called slices. The images can be stored on a computer or printed on film. One exam produces dozens or ...

  • Special Topic

    MRI and low back pain

    and are among the most common health complaints. Almost everyone will have back pain at some time in their life. Most of the time, the exact cause of the pain cannot be found. An MRI scan is an imaging test that can create detailed pictures of the spine. This article focuses on MRI scans to ...

  • Disease

    MRSA

    MRSA stands for methicillin-resistantStaphylococcus aureus. MRSA is a “staph” germ that does not get better with the first-line antibiotics that usually cure staph infections. When this occurs, the germ is “resistant”to the antibiotic.

  • Special Topic

    Mucopolysaccharides

    Mucopolysaccharides are long chains of sugar molecules that are found throughout the body, often in mucus and in fluid around the joints. They are more commonly called glycosaminoglycans.

  • Disease

    Mucormycosis

    Fungal infections are caused by microscopic organisms (fungi) that can live on the skin. They can live on the dead tissues of the hair, nails, and outer skin layers.

    Mucormycosis is a fungal infection of the sinuses, brain, or lungs that occurs in some people with a weakened immune system.

  • Special Topic

    Mucosa

    The mucosa, or mucous membrane, is a type of tissue that lines the nasal cavity. Mucous membranes are usually moist tissues that are bathed by secretions such as in the nose.

    Mucosa is moist tissue that lines certain parts of the inside of your body. It is in your nose, mouth, lungs, and the urinary and digestive tracts. Glands in this tissue release a thick fluid called mucus.

  • Disease

    Mucous cyst

    Mouth ulcers are caused by many disorders. These include canker sores, leukoplakia, gingivostomatitis, oral cancer, oral lichen planus, oral thrush, and similar disorders.

    A mucous is a painless, thin sac on the inner surface of the lips. It contains clear fluid.

  • Disease

    Multi-infarct dementia

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Multi-infarct dementia (MID) is a form of dementia caused by a series of small . is a loss of brain function that occurs with certain diseases. It affects memory, thinking, language, judgment, and behavior.

  • Disease

    Multifocal atrial tachycardia

    The intrinsic conduction system sets the basic rhythm of the beating heart by generating impulses which stimulate the heart to contract.

    Multifocal atrial tachycardia is a that occurs when too many signals (electrical impulses) are sent from the upper heart (atria) to the lower heart (ventricles).

  • Disease

    Multiple endocrine neoplasia (MEN) I

    Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).

    Multiple endocrine neoplasia (MEN) type I is disease passed down through families in which one or more of the endocrine glands are overactive or form a tumor. Endocrine glands most commonly involved include: Pancreas Parathyroid Pituitary

  • Disease

    Multiple endocrine neoplasia (MEN) II

    Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).

    Multiple endocrine neoplasia, type II (MEN II) is disorder passed down through families in which one or more of the endocrine glands are overactive or form a tumor. Endocrine glands most commonly involved include: Adrenal gland (about half the time) Parathyroid gland (20% of the time) Thyroid gland ...

  • Disease

    Multiple lentigines syndrome

    Pectus excavatum is a condition in which the "breast bone" (sternum) appears sunken and the chest concave.  It is sometimes called  "funnel chest".  The majority of these cases are not associated with any other condition (isolated findings).  However, some syndromes include pectus excavatum.

    Multiple lentigines syndrome is an inherited disorder in which there is an increased number of lentigines (freckle-like spots) on the body.

  • Disease

    Multiple myeloma

    The immune system protects the body from potentially harmful substances. The inflammatory response (inflammation) is part of innate immunity. It occurs when tissues are injured by bacteria, trauma, toxins, heat or any other cause.

    Multiple myeloma is that starts in the plasma cells in bone marrow. Bone marrow is the soft, spongy tissue found inside most bones. It helps make blood cells. Plasma cells help your body fight infection by producing proteins called antibodies. With multiple myeloma, plasma cells grow out of ...

  • Disease

    Multiple sclerosis

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Multiple sclerosis is an that affects the brain and spinal cord ().

  • Special Topic

    Multiple sclerosis - resources

    Muscular atrophy is the decrease in size and wasting of muscle tissue.  Muscles that lose their nerve supply can atrophy and simply waste away.

  • Disease

    Multiple system atrophy

    The central nervous system is comprised of the brain and spinal cord. The peripheral nervous system includes all peripheral nerves.

    Multiple system atrophy (MSA) is a rare condition that causes symptoms similar to . However, patients with MSA have more widespread damage to the part of the nervous system that controls important functions such as heart rate, blood pressure, and sweating.

  • Poison

    Multiple vitamin overdose

    Multiple vitamin occurs when someone accidentally or intentionally takes more than the normal or recommended amount of multivitamin supplements. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your ...

  • Disease

    Mumps

    There are several pairs of salivary glands in different locations: a major pair in front of the ears (parotid glands); two major pair on the floor of the mouth (sublingual and submaxillary glands); and several minor pairs within the lips, cheeks, and tongue.

    Mumps is a contagious disease that leads to painful swelling of the salivary glands. The salivary glands produce saliva, a liquid that moistens food and helps you chew and swallow. See also:

  • Disease

    Munchausen syndrome by proxy

    Munchausen syndrome by proxy is a form of in which a parent induces real or apparent symptoms of a disease in a child.

  • Symptoms

    Muscle aches

    Muscle pain is most frequently related to tension, overuse, or muscle injury from exercise or physically demanding work. Muscle aches and pains are common and can involve more than one muscle at the same time. Muscle pain can also involve the soft tissues that surround muscles. These structures, which are often referred to as connective tissues, include ligaments, tendons, and fascia (thick bands of tendons).

    Muscle aches and pains are common and can involve more than one muscle. Muscle pain also can involve ligaments, tendons, and fascia, the soft tissues that connect muscles, bones, and organs. See also:

  • Symptoms

    Muscle atrophy

    People may lose 20 to 40 percent of their muscle -- and, along with it, their strength -- as they age. Scientists have found that a major reason people lose muscle is because they stop doing everyday activities that use muscle power, not just because they grow older.

    Muscle atrophy is the wasting or loss of tissue.

  • Test

    Muscle biopsy

    A muscle biopsy involves removal of a plug of tissue usually by a needle to be later used for examination.  Sometimes more than one needle insertion may be needed to obtain a large enough specimen.  If there is a patchy condition expected an open biopsy may be used.  Open biopsy involves a small incision through the skin and into the muscle, so that a sample of muscle tissue can be removed from the affected area.  There may be some slight bruising or bleeding at the site but the risks are minimal with the procedure.

    A muscle biopsy is the removal of a small piece of muscle tissue for examination.

  • Symptoms

    Muscle cramps

    Clasp your hands behind your back with your palms facing up. Pull your hands down and press your shoulder blades together. Your chest should stick out. Hold for 10-20 seconds. You should feel the stretch in your upper arms and chest.

    Muscle cramps are when a muscle gets tight (contracts) without you trying to do so. The muscle gets tight and does not relax. Cramps may involve all or part of one or more muscles. The most commonly involved muscle groups are: Back of the lower leg/calf Back of the thigh (hamstrings) Front of the ...

  • Symptoms

    Muscle function loss

    Muscle function loss is when a muscle doesn’t work or move normally. The medical term for complete loss of muscle function is paralysis.

  • Special Topic

    Muscle strain treatment

    Treatment for leg strain

    Question: How do you treat a ? Answer: Rest the strained muscle and apply ice for the first few days after the injury. Anti-inflammatory medicines or acetaminophen (Tylenol) also help reduce pain and swelling. As the pain decreases, you can use heat on the muscle. Stretching and light exercises to ...

  • Symptoms

    Muscle twitching

    Muscle tissue is composed primarily of contractile cells. Contractile cells have the ability to produce movement.

    Muscle twitches are fine movements of a small area of muscle.

  • Disease

    Muscular dystrophy

    Superficial muscles are close to the surface of the skin. Muscles which lie closer to bone or internal organs are called deep muscles.

    Muscular dystrophy is a group of inherited disorders that involve and loss of muscle tissue, which get worse over time.

  • Special Topic

    Muscular dystrophy - resources

    Muscular atrophy is the decrease in size and wasting of muscle tissue.  Muscles that lose their nerve supply can atrophy and simply waste away.

  • Disease

    Myasthenia gravis

    Superficial muscles are close to the surface of the skin. Muscles which lie closer to bone or internal organs are called deep muscles.

    Myasthenia gravis is a neuromuscular disorder. Neuromuscular disorders involve the muscles and the nerves that control them.

  • Special Topic

    Myasthenia gravis - resources

    Muscular atrophy is the decrease in size and wasting of muscle tissue.  Muscles that lose their nerve supply can atrophy and simply waste away.

  • Test

    Mycobacterial culture

    During a liver biopsy, a needle is inserted into the liver and a tissue sample is withdrawn and sent to the laboratory for testing. The test is performed to determine the presence of tuberculosis infection in the liver.

    Mycobacterial culture is a test to look for the bacteria that cause and similar infections. See also:

  • Disease

    Mycoplasma pneumonia

    Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.

    Mycoplasma pneumonia is an infection of the lungs by the bacteria Mycoplasma pneumoniae (M. pneumoniae). See also:

  • Special Topic

    Myelin

    Myelin and nerve structure

    Myelin is an insulating layer that forms around nerves, including those in the brain and spinal cord. It is made up of protein and fatty substances. The purpose of the myelin sheath is to allow impulses to transmit quickly and efficiently along the nerve cells. If myelin is damaged, the impulses ...

  • Disease

    Myelofibrosis

    Myelofibrosis is a disorder of the bone marrow, in which the marrow is replaced by scar (fibrous) tissue.

  • Disease

    Myelomeningocele

    Spina bifida is a congenital disorder (birth defect) in which the backbone and spinal canal do not close before birth. In severe cases, this can result in the spinal cord and its covering membranes protruding out of an affected infant's back. Spina bifida may also be nearly inconsequential, or may be reparable through surgery.

    Myelomeningocele is a birth defect in which the backbone and spinal canal do not close before birth. The condition is a type of spina bifida.

  • Test

    Myocardial biopsy

    When a small piece of heart muscle tissue is needed for examination, a heart biopsy can be performed.  A catheter is carefully threaded into an artery or vein to gain access into the heart. A bioptome (catheter with jaws in its tip) is then introduced. Once the bioptome is in place, three to five small pieces of tissue from the heart muscle are removed.  The test is performed routinely after heart transplantation to detect potential rejection. It may also be performed when cardiomyopathy, myocarditis, cardiac amyloidosis, or other disorders are suspected.

    Myocardial biopsy is the removal of a small piece of heart muscle for examination.

  • Disease

    Myocardial contusion

    The interior of the heart is composed of valves, chambers, and associated vessels.

    Myocardial contusion is a bruise of the heart .

  • Disease

    Myocarditis

    Myocarditis is inflammation of the heart muscle. See also:

  • Disease

    Myocarditis - pediatric

    Myocarditis

    Pediatric myocarditis is inflammation of the heart muscle in an infant or young child.

  • Test

    Myoglobin - blood

    Blood (serum) myoglobin is a test that measures the amount of myoglobin in the blood. Myoglobin is a protein in heart and skeletal muscles. When you exercise, your muscles use up any available oxygen. Myoglobin has oxygen attached to it, which provides extra oxygen for the muscles to keep at a high ...

  • Test

    Myoglobin - urine

    A "clean-catch" urine sample is performed by collecting the sample of urine in midstream. Men or boys should wipe clean the head of the penis. Women or girls need to wash the area between the lips of the vagina with soapy water and rinse well. A small amount of urine should initially fall into the toilet bowl before it is collected (this clears the urethra of contaminants). Then, in a clean container, catch about 1 to 2 ounces of urine and remove the container from the urine stream. The container is then given to the health care provider.

    Urine myoglobin is a test to detect the presence of myoglobin in a sample of urine. Myoglobin is a protein in heart and skeletal muscles. When a muscle is exercised, it uses up available oxygen. Myoglobin has oxygen attached to it, which provides extra oxygen for the muscle to keep up a high level ...

  • Disease

    Myopathic changes

    Superficial muscles are close to the surface of the skin. Muscles which lie closer to bone or internal organs are called deep muscles.

    Myopathic changes are weakness or biopsy results that suggest a muscle disorder. The muscle disorder can be inherited, such as , or acquired, such as alcoholic myopathy.

  • Disease

    Myositis

    Myositis is an inflammation or swelling of the muscles, often caused by injury, infection, or an . See also:

  • Disease

    Myotonia congenita

    Superficial muscles are close to the surface of the skin. Muscles which lie closer to bone or internal organs are called deep muscles.

    Myotonia congenita is an inherited condition that affects muscle relaxation. It is congenital, meaning that it is present from birth.

  • Poison

    Myristica oil poisoning

    Myristica oil is a clear liquid that smells like the spice nutmeg. Myristica oil poisoning occurs when someone swallows this substance. This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local ...