What Is Alzheimer’s Disease? Is It Reversible?

Brain disorder happens in stages, medications can ease symptoms

Older woman with confusion, memory loss, part of Alzheimer's symptoms.

Brain disorder happens in stages, medications can ease symptoms

Alzheimer’s disease is a brain disorder that gets worse over time but whose symptoms can be managed to help slow progression of the disease.

The disease develops in stages and affects memory, thinking, learning and ability to carry out simple daily activities. Many in later stages of the disease cannot care for themselves and must depend on family members and friends for their care.

While there is no cure for Alzheimer’s, research continues in earnest for a cure and better treatments. Alzheimer’s is the most common cause of dementia among older adults. More than six million people — mainly 65 and older — are living with Alzheimer’s disease in the United States — and the numbers are growing.

“As the aging population increases and the disease becomes more common, we are learning more and more about diagnosis, symptoms and treatment,” says Gregory Sahagian, MD, a neurologist at Scripps. “We have greater understanding of how Alzheimer’s disease affects the brain, and this has resulted in promising new research.”

What are symptoms of Alzheimer’s disease?

Alzheimer’s disease develops in stages. Memory loss is one of the first symptoms to develop. In the early stages, a person may have difficulty remembering recent events or conversations. They may repeat themselves as a result.

As the disease progresses, other symptoms develop. Short-term memory progresses into impairment of other cognitive functions, such as recognition, language and everyday living skills.

Early diagnosis and medications help with treatment. Certain medications can help relieve symptoms, delay progression of the disease and improve quality of life.

Healthy living, including exercising, and keeping certain underlying conditions under control, including high blood pressure, may help reduce the risk for the disease.

What are risk factors?

Anyone can get Alzheimer’s disease, but certain people are a higher risk. It most often happens in people 65 and older.

  • By age 65, one in 10 people have it.
  • By age 85, nearly half the people in this age group have it.

Early onset is seen in less than 10 percent of cases.

Genetic and environmental factors and severe or repeated traumatic brain injuries are other risk factors.

What causes Alzheimer’s disease?

Alzheimer’s disease is characterized by the degeneration or breakdown of the cognitive system. It is the third leading cause of death in California and sixth leading cause of death in the United States.

The exact causes of the disease are not fully known at this time.

People who develop the disease may be affected by a combination of genetic, lifestyle and environmental factors that affect the brain over time. A key feature is the presence of plaques and tangles in the brain. They block connection between the nerve cells that transmit messages between different parts of the brain and from the brain to muscles and organs.

How is Alzheimer’s diagnosed?

There is no single test for Alzheimer’s disease. A doctor may do a series of tests to diagnose the condition. They may include memory and cognitive tests, neurological function tests, blood and urine tests, brain imaging tests and genetic testing.

“We can diagnose Alzheimer’s disease through clinical examination. Careful evaluation of the patient’s mental state and a medical history will result in a highly accurate diagnosis,” says Dr. Sahagian.

Screening often starts with your primary care physician. Neurologists and other specialists are often called upon to properly diagnose and manage patients with Alzheimer’s. Often, caregivers, spouses or family member can provide better history than the patients themselves.

Alzheimer’s disease treatment

Two classes of drugs have been approved for treatment of Alzheimer’s symptoms. They help improve memory loss, confusion, and problems with thinking and reasoning related to the disease. They are known as cholinesterase inhibitors — for mild and moderate symptoms — and memantine for moderate to severe symptoms. Doctors sometimes prescribe both together.

These treatments also have the effect of helping patients delay moving into a long-term care facility and to stay in their own homes longer.

Cholinesterase inhibitors

Cholinesterase inhibitors prevent the breakdown of acetylcholine, a neurotransmitter or chemical messenger that plays an important role in learning and memory.

Three types are commonly prescribed:

  • Donepezil (Aricept)
  • Rivastigmine (Exelon)
  • Galantamine (Razadyne)

Side effects may include nausea and upset stomach.


Memantine (Namenda) is prescribed to improve memory, awareness and the ability to perform simple tasks.

It works by preventing excess levels of glutamate, a chemical responsible for carrying nerve signals. People with Alzheimer’s may have too much glutamate in their brain.

Side effects can cause headache, constipation, confusion and dizziness.

Early diagnosis

It’s important to identify people who are at high risk for Alzheimer’s as early as possible.

“The sooner we can diagnose and treat someone with Alzheimer’s disease, the better that person’s quality of life,” Dr. Sahagian says. “If you or a loved one is approaching the age where your risk for Alzheimer’s disease begins to increase, talk to your physician about screening.”