Dementia

Dementia is a general term that refers to an abnormal decline in cognitive function due to disease or damage. Dementia can affect most parts of the brain, but areas that are particularly affected are memory, attention, language, problem solving, and orientation. Dementia is sometimes confused with delirium, which has similar symptoms but is caused in elderly people by a disruption in their lifestyle (surgery, poor sleep, change in environment, etc). Delirium can be reversed, but dementia rarely gets better.

The most common type of dementia is Alzheimer's Disease, but there are many other conditions that can cause dementia. For example, Parkinson's disease, Huntington's disease, AIDS, hypothyroidism, alcoholism or cancer.