Vascular dementia - Causes of vascular dementia

Vascular dementia is caused by reduced blood flow to the brain, which damages and eventually kills the brain cells.

This can happen for a number of reasons, including:

narrowing of the small blood vessels deep inside the brain – this is known as subcortical vascular dementia, or small vessel disease
a stroke (where the blood supply to part of the brain is suddenly cut off, usually as the result of a blood clot) – this is sometimes called post-stroke dementia, or single-infarct dementia
lots of "mini-strokes" that cause tiny, but widespread, damage to the brain – this is known as multi-infarct dementia

In some people, the damage to the brain may be caused by Alzheimer's disease in addition to one of these conditions. This is known as mixed dementia.

Who's most at risk?

Things that can increase your chances of developing vascular dementia in later life include:

high blood pressure (hypertension)
smoking
poor diet
high blood cholesterol
lack of exercise
being overweight or obese
diabetes
excessive alcohol consumption
an irregular heartbeat (atrial fibrillation)

These problems can result in damage to the blood vessels in and around the brain, or cause blood clots to develop inside them.

Can I reduce my risk?

By making healthy lifestyle changes – such as stopping smoking and exercising regularly – and treating any health conditions you have, you may be able to reduce your risk of developing vascular dementia.

This may also help slow down or stop the progression of vascular dementia if you are diagnosed in the early stages.

Read more about treating vascular dementia.

However, there are some things you can't change that can increase your risk of vascular dementia, such as:

your age – the risk of vascular dementia increases as you get older, with people over 65 most at risk
your family history – your risk of problems such as strokes is higher if a close family member has had them
your ethnicity – if you are south Asian, African or Caribbean, your risk of stroke is higher, as rates of diabetes and high blood pressure are higher in these groups

In rare cases, unavoidable genetic conditions can also increase your risk of vascular dementia.

For example, small vessel disease can occur as the result of an inherited disorder called cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

This is caused by a faulty gene that makes the blood vessels in the brain more susceptible to changes.