Alzheimer's disease is a brain disorder that gets worse over time. It's characterized by changes in the brain that lead to deposits of certain proteins. Alzheimer's disease causes the brain to shrink and brain cells to eventually die. Alzheimer's disease is the most common cause of dementia — a gradual decline in memory, thinking, behavior and social skills. These changes affect a person's ability to function.

The early signs of the disease include forgetting recent events or conversations. Over time, it progresses to serious memory problems and loss of the ability to perform everyday tasks. Forgetfulness does not necessarily mean there is a disease process going on. The natural aging process can affect memory as well.

There is no treatment that cures Alzheimer's disease. Medicines may improve or slow the progression of symptoms. In advanced stages, severe loss of brain function can cause dehydration, malnutrition or infection. These complications can result in death.


Memory loss is the key symptom of Alzheimer's disease. Early signs include difficulty remembering recent events or conversations. But memory gets worse and other symptoms develop as the disease progresses.


Brain changes associated with Alzheimer's disease can lead to growing trouble with:



Everyone has memory lapses at times, but the memory loss associated with Alzheimer's disease persists and gets worse. Over time, memory loss affects the ability to function at work or at home.  People with Alzheimer's disease may:

  1. Repeat statements and questions over and over.
  2. Forget conversations, appointments or events.
  3. Misplace items, often putting them in places that don't make sense.
  4. Get lost in places they used to know well.
  5. Eventually forget the names of family members and everyday objects.
  6. Have trouble finding the right words for objects, expressing thoughts or taking part in conversations.


Thinking and reasoning

Alzheimer's disease causes difficulty:

  1. Concentrating and thinking, especially about abstract concepts such as numbers.
  2. Doing more than one task at once is especially difficult.
  3. It may be challenging to manage finances, balance checkbooks and pay bills on time.
  4. Eventually, a person with Alzheimer's disease may be unable to recognize and deal with numbers.


Making judgments and decisions

Alzheimer's disease causes a decline in the ability to make sensible decisions and judgments in everyday situations. For example, a person may make poor choices in social settings or wear clothes for the wrong type of weather.

It may become harder for someone to respond to everyday problems. For example, the person may not know how to handle food burning on the stove or decisions when driving.

Planning and performing familiar tasks

Routine activities that require completing steps in order become a struggle. This may include planning and cooking a meal or playing a favorite game.

Eventually, people with advanced Alzheimer's disease forget how to do basic tasks such as dressing and bathing.



Changes in personality and behavior

Brain changes that occur in Alzheimer's disease can affect moods and behaviors. Problems may include the following:

  1. Loss of interest in activities.
  2. Social withdrawal.
  3. Mood swings.
  4. Distrust in others.
  5. Anger or aggression.
  6. Changes in sleeping habits.
  7. Loss of inhibitions.
  8. Delusions, such as believing something has been stolen.


Preserved skills

Despite major changes to memory and skills, people with Alzheimer's disease are able to hold on to some skills even as symptoms get worse. Preserved skills may include reading or listening to books, telling stories, sharing memories, singing, listening to music, dancing, drawing, or doing crafts.

When to see a doctor    A number of conditions can result in memory loss or other dementia symptoms. Some of those conditions can be treated. If you are concerned about your memory or other thinking skills, talk to your health care professional.