Strokes explained

Some people are at a higher risk of stroke than others. Factors such as age, gender, race/ethnicity and family history of stroke can't be changed. But you can control other risk factors, such as high blood pressure or cigarette smoking. The earlier you get a condition diagnosed and treatment started, the better the results.

Smoking
In any discussion of prevention, it's most important to look at factors you have control over. Cigarette smoking is the most powerful modifiable stroke risk factor. Smoking almost doubles your risk for ischaemic stroke, independent of other risk factors; it increases your risk for subarachnoid haemorrhage by up to 3.5 per cent. Smoking leads to a higher percentage of strokes in young adults than in older adults. Heavy smokers are at greater risk of stroke than light smokers.

Your relative risk of stroke decreases immediately after you give up smoking, with a major reduction of risk seen after two to four years. Unfortunately, though, it may take several decades for a former smoker's risk to drop to the level of someone who never smoked.

Smoking increases the risk of stroke by promoting atherosclerosis (hardening or furring of the arteries) and increasing the levels of blood-clotting factors, such as fibrinogen. Smoking also increases the damage that results from stroke by weakening the blood vessel walls.