What is Alzheimer’s Disease?
Alzheimer's is a type of dementia that affects memory, thinking, and behavior. Symptoms eventually grow severe enough to interfere with daily tasks.
Alzheimer's is the most common cause of dementia, a general term for memory loss and other cognitive abilities serious enough to interfere with daily life. Alzheimer's disease accounts for 60-80% of dementia cases.
Alzheimer's is not a normal part of aging. The greatest known risk factor is increasing age, and the majority of people with Alzheimer's are 65 and older. Alzheimer’s disease is considered to be younger-onset Alzheimer’s if it affects a person under 65. Younger-onset can also be referred to as early-onset Alzheimer’s. People with younger-onset Alzheimer’s can be in the early, middle or late stage of the disease.
Alzheimer's worsens over time. Alzheimer's is a progressive disease, where dementia symptoms gradually worsen over a number of years. In its early stages, memory loss is mild, but with late-stage Alzheimer's, individuals lose the ability to carry on a conversation and respond to their environment. On average, a person with Alzheimer's lives 4 to 8 years after diagnosis but can live as long as 20 years, depending on other factors.
Alzheimer's as a Continuum
Alzheimer's disease progresses in stages, with the severity of symptoms increasing over time.
Select a stage to learn more.
Asymptomatic
Mild Cognitive Impairment (MCI) due to Alzheimer's Disease
Mild Dementia
Moderate Dementia
Severe Dementia
Alzheimer's has no cure, but three treatments — aducanumab (Aduhelm®), donanemab (Kisunla™) and lecanemab (Leqembi®) — demonstrate that removing beta-amyloid, one of the hallmarks of Alzheimer’s disease, from the brain reduces cognitive and functional decline in people living with early Alzheimer’s. (Aducanumab will be discontinued on Nov. 1, 2024. Please connect with your provider on treatment options.) Other treatments can temporarily slow the worsening of dementia symptoms and improve quality of life for those with Alzheimer's and their caregivers. Today, there is a worldwide effort underway to find better ways to treat the disease, delay its onset and prevent it from developing.
Symptoms of Alzheimer's
The most common early symptom of Alzheimer's is difficulty remembering newly learned information.
Just like the rest of our bodies, our brains change as we age. Most of us eventually notice some slowed thinking and occasional problems with remembering certain things. However, serious memory loss, confusion and other major changes in the way our minds work may be a sign that brain cells are failing.
Alzheimer's changes typically begin in the part of the brain that affects learning. As Alzheimer's advances through the brain it leads to increasingly severe symptoms, including disorientation, mood and behavior changes; deepening confusion about events, time and place; unfounded suspicions about family, friends and professional caregivers; more serious memory loss and behavior changes; and difficulty speaking, swallowing and walking.
People with memory loss or other possible signs of Alzheimer’s may find it hard to recognize they have a problem. Signs of dementia may be more obvious to family members or friends. Anyone experiencing dementia-like symptoms should see a doctor as soon as possible.