Alzheimer's Disease and Dementia

Skip Navigation

Advanced Search

Alzheimer's Disease and Dementia



What is dementia?

What is Alzheimer's?

How common is Alzheimer's?

Why do some people get Alzheimer's?

What are the signs and symptoms of Alzheimer's?

How is Alzheimer's diagnosed?

What are the stages of Alzheimer's?

What are some of the treatments for Alzheimer's?

What are some of the challenges in dealing with Alzheimer's?

Additional resources


What is dementia?

Dementia is a general term used to describe significant loss of intellectual function due to any form of brain disease. Typically, people with dementia experience the following symptoms:

  • severe memory problems
  • trouble with speech
  • difficulty with abstract thinking
  • poor judgment

Some dementia patients also develop emotional and behavioral changes. Many are unable to function on their own and require various degrees of supervision. Dementia is a syndrome—a cluster of symptoms that often occurs together. It can be caused by a number of different conditions or diseases. The doctor first must decide that a person’s symptoms fit the general category of dementia and then try to determine the specific cause.


What is Alzheimer’s?

Alzheimer’s disease is the most common cause of dementia in adults. For reasons that are still mostly unknown, the brain in Alzheimer’s disease slowly deteriorates. Two characteristic changes occur: Inside brain cells, accumulations of protein, called neurofibrillary tangles, begin to form. About the same time, outside of cells in the gray matter of the brain, another abnormal protein, called beta-amyloid, starts to be deposited. The latter are known as senile or amyloid plaques.

At first, the number of tangles and plaques is small, and they are concentrated in areas of the brain that are important for memory. Over time, the number of plaques and tangles increases and spreads throughout the brain. This process eventually results in the death of brain cells and a decrease in the mass of the brain as a whole. This reduction in mass can sometimes be seen on x-rays.


How common is Alzheimer’s?

Alzheimer’s disease is very common. Approximately 5.5 million people in the United States live with Alzheimer’s, and 500,000 new cases are added every year. As the baby boomer generation gets older, those numbers will likely increase. In fact, we expect about 15 million Americans to have Alzheimer’s disease by the year 2050.


Why do some people get Alzheimer’s?

The most important risk factor for Alzheimer’s disease is increasing age (getting older). Before the age of 65 years old, Alzheimer’s is very rare, although it can occur (sometimes called presenile dementia). After the age of 65, the incidence of the disease begins to rise. By the mideighties, almost half of the population will be affected. Alzheimer’s disease is slightly more common in women than in men.

Heredity and genetics may play a role in some cases. People who have a parent or sibling with Alzheimer’s disease have a somewhat greater risk than someone without such a family history. Having a relative with Alzheimer’s does not, however, mean that you are going to get Alzheimer’s. Nor does having no family history mean that you are immune. Genetic factors are usually more important in the comparatively rare cases of early-onset (before age 65) Alzheimer’s disease.

The following factors are associated with an increased risk for developing Alzheimer’s disease:

  • untreated high blood pressure
  • high cholesterol
  • diabetes
  • obesity
  • physical and intellectual inactivity
  • presence of Down’s syndrome

However, these are ‘group statistics’ that apply only to the population as a whole. They do not mean that you will develop Alzheimer’s if you possess one or more of these risk factors.


What are the signs and symptoms of Alzheimer’s?

Some of the warning signs of Alzheimer’s disease include:
  • memory loss that affects skills at work and at home
  • difficulty performing familiar tasks like driving or handling finances
  • disorientation to time and place
  • difficulty with learning and abstract thinking
  • poor judgment
  • marked loss of initiative
  • changes in personality
  • changes in mood and behavior

These symptoms usually develop very slowly over a long period, although sometimes they may appear to start abruptly or to worsen after an injury, illness, or operation.

It is important to stress that milder forms of the symptoms described above can be normal or signs of other conditions. Careful evaluation by an experienced physician is needed to confirm or rule out a diagnosis of Alzheimer’s.


How is the diagnosis of Alzheimer’s disease made?

If your doctor suspects you might have Alzheimer’s disease, they usually guide you through the following diagnostic steps:
  1. Taking a detailed history of the presenting problem. Sometimes specialized questionnaires are also administered
  2. Performing a thorough neurological examination, including assessment of mental state
  3. Testing by a neuropsychologist to precisely determine the extent and nature of memory loss and other impairments. Not all patients require this step
  4. Testing of blood
  5. Scanning the brain using computed tomography (CT) or magnetic resonance imaging (MRI)
  6. Scanning of the brain using positron emission tomography (PET) and amyloid scans, in selected cases
  7. Examining of spinal fluid and genetic testing (in selected cases)


What are the stages of Alzheimer’s disease?

Untreated, Alzheimer’s is a progressive condition. In the early, or mild stage, memory symptoms usually predominate. At the middle, or moderate stage, other symptoms, for example, difficulties with language and complex visual functions, appear, and the patient can no longer perform all of his or her usual activities of daily living.

By the time the late, or severe stage, is reached, the patient may no longer recognize family members or be able to speak. Late stage Alzheimer patients also may develop epileptic seizures, inability to walk, and contractures (tight muscles).

> Next page: Alzheimer's treatments, challenges, and resources


Bottom of Navigation

Legal & Privacy Notices


Payment Assistance

Contact Us

Hospital Accreditation

© 2015 Dignity Health

Barrow Neurological Institute
350 W. Thomas Road
Phoenix, AZ 85013
(602) 406-3000