Causes - Vascular dementia

Vascular dementia is caused by a reduced blood flow to your brain. The reduced blood flow can damage brain cells.

Reduced blood flow can happen:

• when small blood vessels in the brain narrow - this is called subcortical vascular dementia or small vessel disease
• after a stroke - the blood supply to part of the brain is suddenly cut off, usually due to a blood clot
• if the brain is damaged from mini strokes - these are called transient ischaemic attacks (TIAs)

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

Things that increase your risk of vascular dementia

Some things can increase your risk of vascular dementia. These are called risk factors. Some can damage the blood vessels in and around your brain. Others can cause blood clots.

They include:

• high blood pressure (hypertension)
• smoking
• an unhealthy diet
• high blood cholesterol
• lack of exercise
• carrying extra weight or having obesity
• diabetes
• drinking too much alcohol
• atrial fibrillation (a type of irregular heartbeat)
• other types of heart disease

Reducing your risk of vascular dementia

You cannot always prevent vascular dementia. But there are things you can do that may reduce your risk.

Making these lifestyle changes may also help stop dementia getting worse if you're diagnosed in the early stages.

But there are some risk factors you cannot change.

These include your:

• age - people age 65 or older are most at risk
• family history - your risk is higher if a close family member has had similar problems
• ethnicity - some risk factors such as diabetes and high blood pressure are more common in people from South Asia or Africa

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