Alzheimer's Disease Health Center

Alzheimer's Disease Stages

Alzheimer's disease isn't an immediate descent into forgetfulness. Instead, it is a progressive decline in cognitive function that erodes memory and reduces the ability to perform tasks over a period of several years.

Experts have designated a series of Alzheimer's stages that can help patients and their families plan for future care. Each of these stages includes symptoms that are typical as the disease advances.

Alzheimer's stages typically follow this progression: mild Alzheimer's, moderate Alzheimer's, and severe Alzheimer's. It's important to remember that the stages of Alzheimer's disease can vary from person to person. One person's decline may be slower or steadier than another's.

Mild Cognitive Impairment

Everyone becomes forgetful from time to time, especially as they get older. More than half of people over age 65 experience at least some age-related forgetfulness. When memory loss and problems with mental function become more regular, but not yet severe enough to interfere with daily life, people are said to have mild cognitive impairment (MCI). Some people with MCI never get any worse. Others progress to Alzheimer's disease within a few years.

Mild Alzheimer's

Alzheimer's-related changes can begin in the brain as much as 10 to 20 years before the first symptoms appear. As tangles and plaques form in the brain, the areas of brain tissue that are affected become damaged and work less effectively.

In most people with the condition, Alzheimer's develops after age 65. However, in rare cases Alzheimer's can affect people at a younger age. This is called early-onset Alzheimer's and it's linked to genetic changes.

The first sign of early or mild Alzheimer's disease is usually memory loss. A person with mild Alzheimer's may forget where he or she put the car keys, or be unable to remember the names of people and objects. Sometimes people with mild Alzheimer's will substitute a real or made-up word for the one they've forgotten, such as saying "tiger" instead of "cat." The difference between Alzheimer's disease and normal forgetfulness is that the memory loss occurs with regularity.

As the disease progresses, the symptoms may become more noticeable to family, friends, and co-workers. People with mild Alzheimer's may repeat questions, get lost in once-familiar areas, and have trouble remembering what they've just read or heard. It may be difficult, if not impossible, for them to learn new things. As they become more forgetful, they will often get quieter or withdraw from social situations out of embarrassment.

Organizational difficulties and poor judgment are two other hallmarks of mild Alzheimer's. Some people at the mild Alzheimer's stage start to experience moodiness, and their personality changes.

At this stage, dementia can be diagnosed with a mental status exam and testing the person's knowledge of current events as well as their ability to recount their own personal history and perform complex tasks (such as doing math problems or paying bills).