Alzheimer’s disease is a progressive neurologic disorder that causes the brain to shrink (atrophy) and brain cells to die. Alzheimer’s disease is the most common cause of dementia — a continuous decline in thinking, behavioral and social skills that affect a person’s ability to function independently.
Approximately 5.8 million people in the United States age 65 and older live with Alzheimer’s disease. Of those, 80% are 75 years old and older. Out of the approximately 50 million people worldwide with dementia, between 60% and 70% are estimated to have Alzheimer’s disease.
The early signs of the disease include forgetting recent events or conversations. As the disease progresses, a person with Alzheimer’s disease will develop severe memory impairment and lose the ability to carry out everyday tasks.
Medications may temporarily improve or slow progression of symptoms. These treatments can sometimes help people with Alzheimer’s disease maximize function and maintain independence for a time. Different programs and services can help support people with Alzheimer’s disease and their caregivers.
There is no treatment that cures Alzheimer’s disease or alters the disease process in the brain. In advanced stages of the disease, complications from severe loss of brain function — such as dehydration, malnutrition or infection — result in death. (source)
Alzheimer’s disease is a progressive condition, meaning that the symptoms get worse over time. Memory loss is a key feature, and this tends to be one of the first symptoms to develop.
The symptoms appear gradually, over months or years. If they develop over hours or days, a person may require medical attention, as this could indicate a stroke.
Symptoms of Alzheimer’s disease include:
- Memory loss: A person may have difficulty taking in new information and remembering information. This can lead to:
- repeating questions or conversations
- losing objects
- forgetting about events or appointments
- wandering or getting lost
- Cognitive deficits: A person may experience difficulty with reasoning, complex tasks, and judgment. This can lead to:
- a reduced understanding of safety and risks
- difficulty with money or paying bills
- difficulty making decisions
- difficulty completing tasks that have several stages, such as getting dressed
- Problems with recognition: A person may become less able to recognize faces or objects or less able to use basic tools. These issues are not due to problems with eyesight.
- Problems with spatial awareness: A person may have difficulty with their balance, trip over, or spill things more often, or they may have difficulty orienting clothing to their body when getting dressed.
- Problems with speaking, reading, or writing: A person may develop difficulties with thinking of common words, or they may make more speech, spelling, or writing errors.
- Personality or behavior changes: A person may experience changes in personality and behavior that include:
- becoming upset, angry, or worried more often than before
- a loss of interest in or motivation for activities they usually enjoy
- a loss of empathy
- compulsive, obsessive, or socially inappropriate behavior
In 2016, researchers published findings suggesting that a change in the person’s sense of humor might also be an early symptom of Alzheimer’s.
Alzheimer’s is a progressive disease, which means the symptoms will gradually worsen over time. Alzheimer’s is broken down into seven stages:
- Stage 1. There are no symptoms at this stage but there might be an early diagnosis based on family history.
- Stage 2. The earliest symptoms appear, such as forgetfulness.
- Stage 3. Mild physical and mental impairments appear, such as reduced memory and concentration. These may only be noticeable by someone very close to the person.
- Stage 4. Alzheimer’s is often diagnosed at this stage, but it’s still considered mild. Memory loss and the inability to perform everyday tasks is evident.
- Stage 5. Moderate to severe symptoms require help from loved ones or caregivers.
- Stage 6. At this stage, a person with Alzheimer’s may need help with basic tasks, such as eating and putting on clothes.
- Stage 7. This is the most severe and final stage of Alzheimer’s. There may be a loss of speech and facial expressions.