Doctors diagnose the cause of dementia by asking questions about the person’s medical history and doing a physical exam, a mental status exam, and lab and imaging tests. Tests can help the doctor find out if the loss of mental abilities is caused by a condition that can be treated.
Dementia is the loss of cognitive functioning — thinking, remembering, and reasoning — to such an extent that it interferes with a person’s daily life and activities. Some people with dementia cannot control their emotions, and their personalities may change. Dementia ranges in severity from the mildest stage, when it is just beginning to affect a person’s functioning, to the most severe stage, when the person must depend completely on others for basic activities of living.