HomeContact UsSearch: 



From NIHSeniorHealth


AD is the most common cause of dementia among older people. Dementia is the loss of cognitive functioning—thinking, remembering, and reasoning—to such an extent that it interferes with a person’s daily life and activities.

Alzheimer's Disease Defined

Dementia is a brain disorder that seriously affects a person's memory, thinking, and reasoning skills. People with dementia often have trouble thinking and speaking clearly, remembering recent events, and learning new things. Over time, it becomes hard for them to handle everyday activities and take care of themselves. There are many causes of dementia, but Alzheimer's disease is the most common cause of dementia in older persons.


Scientists think that up to 4.5 million people in the United States suffer from Alzheimer's disease. The disease usually begins after age 65 and risk goes up with age. While younger people also may get Alzheimer's disease, it is much less common.


About 5 percent of men and women ages 65 to 74 have Alzheimer's disease, and nearly half of those age 85 and older may have the disease. It is important to note, however, that Alzheimer's disease is not a normal part of aging.


Alzheimer's disease is named after Dr. Alois Alzheimer, a German doctor. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. He found abnormal clumps and tangled bundles of fibers. The clumps are now called amyloid plaques and the tangles are called neurofibrillary tangles. Today, these plaques and tangles in the brain are considered signs of Alzheimer's disease.


Scientists also have found other brain changes in people with Alzheimer's disease. There is a loss of nerve cells and pathways in areas of the brain that are vital to memory and other mental abilities. There also are lower levels of some of the chemicals in the brain that carry complex messages back and forth between nerve cells.


Alzheimer's disease may disrupt normal thinking and memory by blocking these messages between nerve cells.

Symptoms and Diagnosis

Alzheimer's disease begins slowly. At first, the only symptom may be mild forgetfulness. People in the early stage of Alzheimer's disease may have trouble remembering recent events, activities, or the names of familiar people or things. Simple math problems may become hard to solve. Such difficulties may be a bother, but usually they are not serious enough to cause alarm.


However, as the disease goes on, forgetfulness begins to interfere with daily activities. People may forget the way home or find it hard to cope with daily life. Such symptoms are more easily noticed and become serious enough to cause people with Alzheimer's disease or their family members to seek medical help.


People in the middle stages of Alzheimer's disease may forget how to do basic tasks, like brushing their teeth or combing their hair. They can no longer think clearly. They begin to have problems speaking, understanding, reading, or writing. Later on, people with Alzheimer's disease may become anxious, agitated or aggressive, or wander away from home. Eventually, patients need total care.


An early, accurate diagnosis of Alzheimer's disease helps patients and their families plan for the future. It gives them time to discuss care options while the patient can still take part in making decisions. And even though no drug can slow the onset or the progression of Alzheimer's, early diagnosis offers the best chance to treat the symptoms of the disease.


There is no known cure for Alzheimer's, but there are treatments that can prevent some symptoms from getting worse for a limited time. Ongoing research offers clues to the way Alzheimer's develops and the reasons it starts. It also offers hope that some day it may be possible to delay the onset of Alzheimer's, slow its progress, or even prevent it altogether.


Alzheimer's disease develops slowly, starting with mild memory problems and ending in death. The course the disease takes and how fast changes occur vary from person to person. The time from diagnosis to end of life varies. It can be as little as 3 years if the person is over 80 when diagnosed. Or it may be as long as 10 years or more if the person is younger.


A person with Alzheimer's should be under a doctor's care and may see a neurologist, psychiatrist, family doctor, internist, or geriatrician -- a specialist who treats older adults. The doctor can treat the person's physical and behavioral problems and answer the many questions that the person or the family may have.


Also, some medicines may help control behavioral symptoms of Alzheimer's disease such as sleeplessness, agitation, wandering, anxiety, and depression. Treating these symptoms often makes patients more comfortable and makes their care easier for caregivers.


Family members and friends can assist people in the early stages of Alzheimer's in continuing their daily routines, physical activities, and social contacts. People with Alzheimer's should be kept up-to-date about the details of their lives, such as the time of day, where they live, and what is happening at home or in the world.


Memory aids may help in the day-to-day living of patients in the earlier stages of Alzheimer's. Some families find that a big calendar, a list of daily plans, notes about simple safety measures, and written directions describing how to use common household items are very useful aids.