Dementia is the loss of intellectual abilities that is severe enough to interfere with social or occupational functioning. Vascular dementia, also called arteriosclerotic or multi infarct dementia, is caused by the poor circulation of blood in the brain.

See also Map 70 Other nervous disorders (which includes Alzheimer’s disease) and Map 109 Old age.

There is no clear pattern to the map here.

Many people with dementia die of pneumonia, and until recently the death was usually classified as due to pneumonia rather than dementia.

While the likelihood of dementia increases with age, it is not a normal part of growing old: most older people never develop dementia.

The dysfunction caused by dementia is multifaceted and involves memory, behaviour, personality, judgement, attention, spatial relations, language and abstract thought. The intellectual decline is usually progressive.

The risk factors for vascular or multi infarct dementia are the same as those for stroke, including high blood pressure, diabetes, smoking, poor diet and excessive alcohol intake.