While not all the risk factors for a subarachnoid haemorrhage can be prevented, the two leading risk factors can.

These are:

• smoking
• high blood pressure

Smoking

Smoking is a major risk factor for a subarachnoid haemorrhage because it raises your blood pressure. There may also be harmful substances in tobacco smoke that could damage the walls of the arteries which could make it more likely that the aneurysm ruptures (bursts open).

If you decide to stop smoking, your GP will be able to refer you to an NHS Stop Smoking Service, which will help and advise about the best ways to give up. You can also call the NHS Smoking Helpline on 0800 022 4332. Specially trained helpline staff can offer you free expert advice and encouragement.

If you're committed to giving up smoking but don't want to be referred to a stop-smoking service, your GP should be able to prescribe medical treatments to help with any withdrawal symptoms that you may have after quitting.

See Treatment for quitting smoking and Live Well: stop smoking for more information about giving up.

High blood pressure

High blood pressure can often be reduced by eating a healthy diet, moderating your alcohol intake, maintaining a healthy weight and doing regular exercise.

Diet

Cut down on the amount of salt in your food and eat plenty of fruit and vegetables.

Salt raises your blood pressure. The more salt you eat, the higher your blood pressure. Aim to eat less than 6g (0.2oz) of salt a day – about a teaspoonful. Find out more about how to cut down on salt.

Eating a low-fat diet that includes lots of fibre (for example, wholegrain rice, bread and pasta) and plenty of fruit and vegetables has been proven to help lower blood pressure. Fruit and vegetables are full of vitamins, minerals and fibre to keep your body in good condition. You should aim to eat five 80g portions of fruit and vegetables every day.

Find out more about getting your 5 A Day.

Alcohol

Regularly drinking alcohol above the levels recommended by the NHS will raise your blood pressure over time. Staying within the recommended levels is the best way to reduce your risk of developing high blood pressure.

The NHS recommends:

• men shouldn't regularly drink more than 3-4 units a day
• women shouldn't regularly drink more than 2-3 units a day

Find out how many units are in your favourite tipple, track your drinking over time and get tips on cutting down.

Alcohol is also high in calories, which will make you gain weight. This will also increase your blood pressure. Find out how many calories are in popular drinks.

Weight

Being overweight forces your heart to work harder to pump blood around your body, which can raise your blood pressure. Use the BMI healthy weight calculator to find out if you need to lose weight.

If you need to shed some weight, it's worth remembering that losing just a few pounds will make a big difference to your blood pressure and overall health. Get tips on losing weight safely.

Exercise

Being active and taking regular exercise lowers blood pressure by keeping your heart and blood vessels in good condition. Regular exercise can also help you lose weight, which will also help lower your blood pressure.

Adults should do at least 150 minutes (two hours and 30 minutes) of moderate-intensity aerobic activity (i.e. cycling or fast walking) every week. For it to count, the activity should make you feel warm and slightly out of breath. Someone who is overweight may only have to walk up a slope to get this feeling.

Physical activity can include anything from sport to walking and gardening. Get more ideas on being active.

Read more about preventing high blood pressure.