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

This is usually due to:

• narrowing of the small blood vessels deep inside the brain, 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 because of a blood clot), called post-stroke dementia or single-infarct dementia
• lots of "mini strokes" (also called transient ischaemic attacks or TIAs) that cause tiny but widespread damage to the brain, known as multi-infarct dementia

Some people with vascular dementia also have brain damage caused by Alzheimer's disease. This is known as mixed dementia.

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

• high blood pressure (hypertension)
• smoking
• an unhealthy diet
• high blood cholesterol
• lack of exercise
• being overweight or obese
• diabetes
• drinking too much alcohol
• atrial fibrillation – a type of irregular heartbeat (arrhythmia) – and other types of heart disease

These problems increase the risk of damage to the blood vessels in and around your brain, or cause blood clots to develop inside them.

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 chances of getting vascular dementia.

This may also help slow down or stop the progression of vascular dementia if you're diagnosed in the early stages. Find out more about treating vascular dementia.

But there are some things you cannot 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 have a south Asian, African or Caribbean background, your risk of vascular dementia is higher, as related problems such as diabetes and high blood pressure are more common in these groups

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