Find answers to your health-related questions in our health encyclopedia.

  • Disease

    H1N1 influenza (Swine flu)

    The H1N1 virus (swine flu) is an infection of the nose, throat, and lungs. It is caused by the H1N1 influenza virus.

  • Poison

    H2 receptor antagonists overdose

    H2 receptor antagonists are medicines that help decrease stomach acid. H2 receptor antagonist overdose occurs when someone takes more than the normal or...

  • Special Topic

    Haemophilus influenzae Type b (Hib) vaccine - what you need to know

    Haemophilus b conjugate vaccine is one of the recommended childhood immunizations. Over 90% of infants receiving 3 doses of the Hib vaccine gain long-term protection against the illnesses caused by Haemophilus b bacteria.

    All content below is taken in its entirety from the CDC Hib (Haemophilus Influenzae Type b) Vaccine Information Statement (VIS):...

  • Poison

    Hair bleach poisoning

    Hair bleach poisoning occurs when someone swallows hair bleach or splashes it on their skin or in their eyes. This article is for information only. DO NOT...

  • Poison

    Hair dye poisoning

    Hair dye poisoning occurs when someone swallows dye or tint used to color hair. This article is for information only. DO NOT use it to treat or manage an...

  • Symptoms

    Hair loss

    Trichotillomania  is repetitive twisting and twirling of the hair.  The hair loss is usually in a well-defined area with shortened, broken-off hairs and early regrowth of hair.  The scalp is the most commonly involved site, but eyelashes and eyebrows may also be involved.  The hair loss can also be patchy and poorly defined.

    Partial or complete loss of hair is called alopecia.

  • Poison

    Hair spray poisoning

    Hair spray poisoning occurs when someone breathes in (inhales) hair spray or sprays it down their throat or into their eyes. This article is for information...

  • Poison

    Hair straightener poisoning

    Hair straightener poisoning occurs when someone swallows products that are used to straighten hair. This article is for information only. Do NOT use it to...

  • Poison

    Hair tonic poisoning

    Hair tonic is a product used to style the hair. Hair tonic poisoning occurs when someone swallows this substance. This article is for information only. DO...

  • Surgery

    Hair transplant

    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 hair transplant is a surgical procedure to improve baldness.