Progression of Alzheimer's disease (AD) may be divided into several stages. The symptoms in each stage are described below. Their corresponding brain damages are illustrated in Chapter 3.
Very early signs
Memory problems are one of the first signs of AD. Some people with mild AD have a condition called amnestic mild cognitive impairment (MCI). People with MCI have more memory problems than normal people at their age, but their symptoms are not as severe as those with AD. More people with MCI go on to develop AD than those without MCI.
As AD progresses, memory loss continues and changes in other cognitive abilities appear. Symptoms in this stage can include:
In most people with AD, symptoms first appear after age 60. AD is often diagnosed at this stage.
In moderate AD, damage occurs in areas of the brain that control language, reasoning, sensory processing, and conscious thought. Symptoms may include:
People with severe AD cannot communicate and are completely dependent on others for their care. Near the end, the person with AD may be in bed most or all of the time. Their symptoms often include:
[Adapted from: National Institute on Aging, USA]