Dementia is defined as a significant loss of memory and mental function. It is often confused with a temporary forgetfulness resulting from a limited infection underlying illness, stress, depression, or side effects of medication. This makes it difficult to diagnose. Unlike temporary forgetfulness, dementia becomes worse over time.
Common symptoms of dementia include being less able to grasp new ideas and adapt to change, and less concerned with activities or other people. People suffering from dementia may lose their sense of time, forget the day, forget where they are, or even get lost in a familiar place. As the dementia progresses, they will fail to recognize people they know well. They may repeat the same question over and over without realizing it. Their ability to reason and to calculate will be damaged, causing difficulty in making decisions, solving problems, even handling money. Dementia can also cause abrupt changes in personality.
There are many different causes of dementia, but it becomes more frequent with age, and is most often associated with the onset of Alzheimer's disease, which attacks the brain. It is caused by build-up of protein deposits, called plaques, which form tangles in the brain cells, disrupting normal function. Alzheimer's accounts for between 50 percent and 70 percent of all cases of dementia.
Vascular dementia results from problems in the blood circulation to the brain, causing damage from multiple tiny strokes. These occur when a piece of brain tissue supplied by a blood vessel is blocked or interrupted. These strokes may damage specific areas of the brain responsible for speech or language, and also cause dementia. Other causes include Parkinson's disease, a progressive disorder of the nervous system; brain tumors; and multiple sclerosis. A small number of cases are associated with HIV-related illness. All these conditions damage and kill brain cells.