High blood pressure and the risk of dementia
People with persistent high blood pressure are more likely to develop dementia. Taking medication to lower blood pressure may help to reduce the risk.
Does high blood pressure increase the risk of dementia?
Evidence shows that high blood pressure increases a person’s risk of developing dementia.
Long-term research studies have demonstrated that people who had high blood pressure in mid-life (from 40-64 years of age) were more likely to develop dementia in later life, particularly vascular dementia.
Vascular dementia is the second most common form of dementia after Alzheimer's disease. It is caused by reduced blood flow to the brain, which starves brain cells of the oxygen and nutrients they need to function correctly. Brain blood flow can also be affected in Alzheimer’s disease, which may also increase the risk of developing the disease.
Despite the link between vascular dementia and high blood pressure, the results from clinical trials into lowering blood pressure to prevent dementia have so far been inconclusive.
How to reduce the risk of dementia
A lifelong approach to good health is the best way to lower your risk of dementia.
There are some lifestyle behaviours with enough evidence to show that changing them will reduce your risk of dementia.
About high blood pressure
Blood pressure is the force applied to your arteries (the major blood vessels that carry blood to our essential organs) as blood is circulated around the body by the heart. It is measured by your GP using a blood pressure cuff.
Your blood pressure is reported as two numbers.
- The first represents the pressure of blood as the heart contracts to pump the blood. This is the systolic pressure.
- The second is a measure of the blood pressure when the heart rests between beats. This is called diastolic pressure.
- A normal blood pressure reading is around 120/80 mmHg.
High blood pressure, also known as hypertension, is diagnosed when your blood pressure is consistently above 140/90 mmHg. It is a serious condition that is a major cause of heart attack and stroke worldwide. By 2025, it is estimated that 1.56 billion people globally will be diagnosed with high blood pressure.
Things that increase a person’s risk of high blood pressure include a lack of exercise, being overweight or obese, an unhealthy diet that is high in salt, high alcohol consumption, and smoking.
Many of these are also risk factors for dementia. Other factors that can cause high blood pressure include some medical conditions and medicines, or genetics.
How to manage your blood pressure
It is important to first get an accurate idea of what your blood pressure is. In England, it is estimated that 30% of the population has high blood pressure. But due to the lack of symptoms, it may go undiagnosed until someone starts to have problems (such as a heart attack or angina).
You can find out your blood pressure by visiting your GP or a blood pressure booth in your local pharmacy. The NHS recommends that it should be checked every five years.
There are things you can do to lower your blood pressure if it is too high. Lifestyle changes that can help include:
- losing weight
- exercising regularly
- maintaining a healthy low-salt diet
- reducing caffeine consumption
- reducing alcohol consumption
- quitting smoking
High blood pressure can also be controlled through the use of blood pressure medication, which is prescribed by your doctor. These blood pressure-lowering drugs have been shown to be safe and effective. However, it is important to note that they have not been proven or recommended to directly prevent vascular dementia.
If you have high blood pressure, it is important to talk to your doctor before attempting major lifestyle changes or trying a new medication. They can provide you with personalised recommendations and monitor your progress.
A lifelong approach to health is important. High blood pressure can start without showing any symptoms, so it is important to be proactive and find out what your blood pressure is.
There are several ways that high blood pressure affects the brain. High blood pressure causes strain to arteries over time, which leads to the wall of the arteries getting thicker and stiffer. This is called arteriosclerosis.
Fats found in the blood also contribute to the development of the narrowing of the arteries. The narrowing of the arteries can happen in the brain. This means fewer nutrients and less oxygen can get to brain cells which prevents them from functioning correctly.
High blood pressure is also the strongest risk factor for stroke. Strokes occur either when the blood supply of a part of the brain is cut off or when a blood vessel bursts, causing a bleed on the brain. Both types of stroke cause brain cell death which can lead to vascular dementia.
Narrowing of the blood vessels deep inside the brain does not always cause a major stroke. The very small deep blood vessels can be blocked or have small bleeds (microbleeds). These might not cause any symptoms but can gradually accumulate over many years. These changes then become visible on brain scans and are known as small vessel disease. This is a major contributing factor in the development of vascular dementia.
Alzheimer's Society dementia support line
Call 0333 150 3456.
If you are affected by dementia, worried about a diagnosis or a carer, trained staff are ready to give you the support you need. Opening hours (excluding bank holidays): Mon to Weds: 9am – 8pm, Thurs and Fri: 9am – 5pm, Sat and Sun: 10am – 4pm.
Last reviewed: December 2023
Next review: December 2025