Memory problems are one of the first signs of AD. Some people with memory problems have a condition called amnestic mild cognitive impairment (MCI), which means they have more memory problems than normal for people their age, but their symptoms are not as severe as those with AD. More people with MCI, compared with those without MCI, go on to develop AD.
Mild Alzheimer's disease
As Alzheimer's disease progresses, memory loss continues and changes in other cognitive abilities appear. Problems can include getting lost, trouble handling money and paying bills, repeating questions, taking longer to complete normal daily tasks, poor judgment, and small mood and personality changes. People often are diagnosed in this stage.
Moderate Alzheimer's disease
As Alzheimer's disease progresses, plaques and tangles spread throughout the brain, starting in the neocortex. By the final stage, damage is widespread and brain tissue has shrunk significantly. In this stage, damage occurs in areas of the brain that control language, reasoning, sensory processing and conscious thought. Memory loss and confusion increase, and people begin to have problems recognizing family and friends. They may be unable to learn new things, carry out tasks that involve multiple steps (such as getting dressed) or cope with new situations. They may have hallucinations, delusions and paranoia and may behave impulsively. Imaging of the brain often reveals atrophy of the parietal and medial temporal lobes.
Severe Alzheimer's disease
By the final stage, plaques and tangles have spread throughout the brain, and brain tissue has shrunk significantly. People with severe Alzheimer's cannot communicate and are completely dependent on others for their care. Near the end, the person may be in bed most or all of the time, as the body shuts down. Generalized cerebral atrophy with posterior predominance may be seen on imaging.