Overview
Alzheimer’s disease is the most common cause of dementia. Alzheimer’s disease is the biological process that begins with the appearance of a buildup of proteins in the form of amyloid plaques and neurofibrillary tangles in the brain. This causes brain cells to die over time and the brain to shrink.
About 6.9 million people in the United States age 65 and older live with Alzheimer’s disease. Among them, more than 70% are age 75 and older. Of the more than 55 million people in the world with dementia, 60% to 70% are estimated to have Alzheimer’s disease.
Early symptoms of Alzheimer’s disease include forgetting recent events or conversations. Over time, Alzheimer’s disease leads to serious memory loss and affects a person’s ability to do everyday tasks.
There is no cure for Alzheimer’s disease. In advanced stages, loss of brain function can cause dehydration, poor nutrition or infection. These complications can result in death.
But medicines may improve symptoms or slow the decline in thinking. Programs and services can help support people with the disease and their caregivers.
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Symptoms
Memory loss is the key symptom of Alzheimer’s disease. Early in the disease, people may have trouble remembering recent events or conversations. Over time, memory gets worse and other symptoms occur.
At first, someone with the disease may be aware of having trouble remembering things and thinking clearly. As signs and symptoms get worse, a family member or friend may be more likely to notice the issues.
Brain changes from Alzheimer’s disease lead to the following symptoms that get worse over time.
Memory
Everyone has trouble with memory at times, but the memory loss related to Alzheimer’s disease is lasting. Over time, memory loss affects the ability to function at work and at home.
People with Alzheimer’s disease may:
- Repeat statements and questions over and over.
- Forget conversations, appointments or events.
- Misplace items, often putting them in places that don’t make sense.
- Get lost in places they used to know well.
- Forget the names of family members and everyday objects.
- Have trouble finding the right words, expressing thoughts or having conversations.
Thinking and reasoning
Alzheimer’s disease causes trouble concentrating and thinking, especially about abstract concepts such as numbers. Doing more than one task at once is especially hard. It may be challenging to manage finances, balance checkbooks and pay bills on time. Eventually people with Alzheimer’s disease may not recognize numbers.
Making judgments and decisions
Alzheimer’s disease makes it hard to make sensible decisions and judgments. People with Alzheimer’s disease may make poor choices in social settings or wear clothes for the wrong type of weather. Everyday problems may be hard to solve. Someone with Alzheimer’s disease may not know how to handle food burning on the stove or how to make decisions when driving.
Planning and performing familiar tasks
Routine activities that involve completing steps in a certain order also can be hard for people with Alzheimer’s disease. They may have trouble planning and cooking a meal or playing a favorite game. As Alzheimer’s disease becomes advanced, people 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. Symptoms may include:
- Depression.
- Loss of interest in activities.
- Social withdrawal.
- Mood swings.
- Not trusting others.
- Anger or aggression.
- Changes in sleeping habits.
- Wandering.
- Loss of inhibitions.
- Delusions, such as believing something has been stolen when it hasn’t.
Preserved skills
Despite major changes to memory and skills, people with Alzheimer’s disease are able to keep some skills even as symptoms get worse. These are known as preserved skills. They may include reading or listening to books, telling stories, sharing memories, singing, listening to music, dancing, drawing, or doing crafts.
Preserved skills may last longer because they’re managed by parts of the brain affected in later stages of the disease.
When to see a doctor
Several conditions can cause 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 healthcare professional.
If you are concerned about the thinking skills you notice in a family member or friend, ask about going together to talk to a healthcare professional.