Overweight, obesity and stroke

What happens in the brain during a stroke?

A stroke occurs when blood flow to part of the brain is blocked by a blood clot, which is called an ischaemic stroke, or when a blood vessel ruptures and causes bleeding in the brain.

In an ischaemic stroke, the affected part of the brain is deprived of oxygen and nutrients, which can quickly damage brain cells. In a brain haemorrhage, both the bleeding itself and increased pressure in the brain can cause damage to brain tissue.

The symptoms depend on which part of the brain is affected and can include sudden difficulty speaking, weakness or paralysis on one side of the body, visual disturbances, balance problems or other neurological symptoms.

Stroke is an acute and potentially life-threatening condition. If you suspect a stroke, call 112 immediately. Rapid treatment can reduce the risk of permanent brain damage and improve the prognosis.

How do overweight and high blood pressure affect your health?

Overweight and obesity are associated with an increased risk of high blood pressure. High blood pressure is, in turn, one of the most important modifiable risk factors for stroke and other cardiovascular disease.

With overweight and obesity, several changes occur in the body that can contribute to increased blood pressure. Among other things, blood volume can increase and blood pressure regulation can be affected through changes in the nervous system, hormonal system and kidney function. Insulin resistance and other metabolic changes can also play a role.

Long-term high blood pressure puts strain on the blood vessels and can, over time, contribute to blood vessel damage and atherosclerosis. It increases the risk of both ischaemic stroke, which is caused by a blood clot, and brain haemorrhage.

High blood pressure often causes no clear symptoms and can therefore be present for a long time without being detected. Regular blood pressure checks are therefore important, particularly for people with other risk factors for cardiovascular disease.

How you can reduce the risk of stroke

The risk of stroke is influenced by several factors. Some cannot be changed, such as age and heredity, but many of the most important risk factors can be influenced through lifestyle habits and treatment of underlying conditions.

To reduce the risk of stroke, it is particularly important to:

• Keep your blood pressure under control. High blood pressure is one of the most important modifiable risk factors for stroke. Regular blood pressure checks can help detect and treat high blood pressure in time.
• Avoid smoking. Smoking increases the risk of cardiovascular disease and stroke. Stopping smoking is therefore an important preventive measure.
• Be physically active and eat healthily. Regular physical activity and healthy eating habits can contribute to better blood pressure, blood sugar, blood lipids and weight.
• Lose weight if you have overweight or obesity. Weight loss can improve several risk factors for stroke, including high blood pressure, insulin resistance and type 2 diabetes. Even moderate weight loss can have positive effects on metabolic health.
• Limit alcohol consumption. High alcohol consumption can, among other things, contribute to high blood pressure and increase the risk of stroke.
• Detect and treat other risk factors. Type 2 diabetes, high blood lipids and atrial fibrillation are examples of conditions that can increase the risk of stroke and may need treatment.

For people with overweight or obesity, it is therefore relevant to consider overall metabolic health, not just body weight. Blood pressure, blood sugar, blood lipids, physical activity and other lifestyle habits are important parts of the overall risk of cardiovascular disease.

How can medical weight loss affect the risk of cardiovascular disease?

For people with obesity, GLP-1-based weight treatment can contribute to significant weight loss. Weight loss and improved metabolic health can, in turn, have positive effects on several risk factors for cardiovascular disease, including blood pressure and blood sugar.

There is also research showing a reduced risk of serious cardiovascular events in certain patient groups. The SELECT study included more than 17,000 people with overweight or obesity who already had established cardiovascular disease, but not diabetes. Participants received either semaglutide 2.4 mg or placebo. During an average follow-up of approximately 40 months, cardiovascular death, non-fatal heart attack or non-fatal stroke occurred in 6.5 per cent of participants treated with semaglutide, compared with 8.0 per cent in the placebo group. This corresponds to a 20 per cent lower relative risk for the composite outcome.

Medical weight treatment can be part of a broader strategy to reduce cardiovascular risk in people with obesity. Which treatment is appropriate must always be assessed individually based on the person's health and other risk factors.

Frequently asked questions about stroke and health

Can overweight and obesity increase the risk of stroke?

Yes. Overweight and obesity are associated with an increased risk of stroke and often occur together with other risk factors, such as high blood pressure, type 2 diabetes and high blood lipids. At the same time, the risk is influenced by many other factors, including age, smoking, physical activity and heredity.

Can weight loss reduce the risk of stroke?

For people with overweight or obesity, weight loss can improve several important risk factors for stroke, including blood pressure, blood sugar and metabolic health. How this affects an individual's risk of stroke varies and depends on several factors.

Why is high blood pressure an important risk factor for stroke?

Long-term high blood pressure puts strain on the blood vessels and can, over time, contribute to blood vessel damage. It increases the risk of both ischaemic stroke, which is caused by a blood clot, and stroke caused by a brain haemorrhage. Because high blood pressure often causes no clear symptoms, regular checks are important.

What can I do myself to reduce the risk of stroke?

Many risk factors can be influenced. Not smoking, being physically active, eating healthily, limiting alcohol consumption and, when needed, losing weight can contribute to better cardiovascular health. It is also important to detect and treat conditions such as high blood pressure, diabetes, high blood lipids and atrial fibrillation.

What should I do if I suspect a stroke?

If you suspect a stroke, call 112 immediately. Stroke is an acute condition where rapid treatment can reduce the risk of permanent brain damage. Call 112 even if the symptoms are mild or go away. Temporary stroke symptoms may be caused by a TIA (transient ischaemic attack), which is caused by a temporary disruption of blood flow to the brain and can be a warning sign of stroke.