The exact cause of Alzheimer disease (AD) is not known. Research shows that certain changes in the brain lead to AD developing.
You are more likely to develop AD if you:
- Are older. But developing AD is not a part of normal aging.
- Have a close relative, such as a brother, sister, or parent, with AD.
- Have certain genes linked to AD.
The following may also increase the risk:
- Being female
- Having heart and blood vessel problems due to high cholesterol
- History of head trauma
There are two types of AD:
- Early onset AD: Symptoms appear before age 60. This type is much less common than late onset. It tends to get worse quickly. Early onset disease can run in families. Several genes have been identified.
- Late onset AD: This is the most common type. It occurs in people age 60 and older. It may run in some families, but the role of genes is less clear.
AD symptoms include difficulty with many areas of mental function, including:
- Emotional behavior or personality
- Thinking and judgment (cognitive skills)
AD usually first appears as forgetfulness.
Mild cognitive impairment (MCI) is the stage between normal forgetfulness due to aging, and the development of AD. People with MCI have mild problems with thinking and memory that do not interfere with daily activities. They are often aware of the forgetfulness. Not everyone with MCI develops AD.
Symptoms of MCI include:
- Difficulty performing more than one task at a time
- Difficulty solving problems
- Forgetting recent events or conversations
- Taking longer to perform more difficult activities
Early symptoms of AD can include:
- Difficulty performing tasks that take some thought, but used to come easily, such as balancing a checkbook, playing complex games (bridge), and learning new information or routines
- Getting lost on familiar routes
- Language problems, such as trouble finding the name of familiar objects
- Losing interest in things previously enjoyed and flat mood
- Misplacing items
- Personality changes and loss of social skills
As AD becomes worse, symptoms are more obvious and interfere with the ability to take care of oneself. Symptoms may include:
- Change in sleep patterns, often waking up at night
- Delusions, depression, and agitation
- Difficulty doing basic tasks, such as preparing meals, choosing proper clothing, and driving
- Difficulty reading or writing
- Forgetting details about current events
- Forgetting events in one’s life history and losing self-awareness
- Hallucinations. arguments, striking out, and violent behavior
- Poor judgment and loss of ability to recognize danger
- Using the wrong word, mispronouncing words, or speaking in confusing sentences
- Withdrawing from social contact
People with severe AD can no longer:
- Recognize family members
- Perform basic activities of daily living, such as eating, dressing, and bathing
- Understand language
Other symptoms that may occur with AD: