ementia is the general term used to describe a decline in mental ability that interferes with daily life. Alzheimer’s disease is the most common form of dementia, accounting for over half of dementia cases.
While Alzheimer’s is not a normal part of growing older, aging is the disease’s greatest risk factor—the majority of people with Alzheimer’s are over 65 years old. But approximately 5 percent of people with the disease have early onset—or younger-onset—Alzheimer’s, which often appears when sufferers are in their 40s or 50s.
Alzheimer’s is a progressive disease, so its dementia symptoms gradually worsen over time. The disease typically advances in three general stages—mild (early-stage), moderate (middle-stage), and severe (late-stage).
Because Alzheimer’s affects people in diverse ways, those with the diagnosis experience its effects differently. In its early stages, memory loss is typically mild; but with late-stage Alzheimer’s, individuals lose the ability to carry on a conversation and respond to their environment.