Risk factors are things that increase the chance of having a stroke. Certain risk factors are important contributors to all types of strokes while other factors may favour a specific type of stroke.
High blood pressure is the most important risk factor for stroke. In fact, stroke risk varies directly with blood pressure. Effective treatment of high blood pressure may be the reason that death rates for stroke have greatly decreased in recent years.
Increasing age. The chance of having a stroke more than doubles for each decade of life after age 55.
Prior stroke. The risk of stroke for someone who has already had one is many times higher that of a person who has not.
Cigarette smoking. Cigarette smoking is an important risk factor for stroke. The nicotine and carbon monoxide in cigarette smoke damage the heart and blood vessels in many ways. The use of birth control pills combined with cigarette smoking greatly increases stroke risk.
Male sex. Overall, men have about a 20 per cent greater chance of stroke than women. Among people under age of 65, the risk for men is even greater when compared to that of women.
Heredity (family history) and race. The chance of stroke is greater in people who have a family history of stroke. African Americans have a much higher risk of death and disability from a stroke than people with light skin, in part because people with dark skin have a greater incidence of high blood pressure.
Diabetes mellitus is an independent risk factor for stroke and is strongly correlated with high blood pressure. While diabetes is treatable, having it still increases a person’s risk of stroke.
Carotid artery disease. The carotid arteries in the neck supply blood to the brain. A carotid artery damaged by atherosclerosis (a fatty buildup of plaque in the artery wall) may become blocked by a blood clot and cause a stroke.
Heart disease. A diseased heart increases the risk of stroke. People with heart problems have greater than twice the risk of stroke as those without heart problems. Heart attack is also the major cause of death among survivors of stroke.
Atrial fibrillation (the rapid, uncoordinated beating of the heart’s upper chambers) raises the risk for embolic stroke.
Transient ischaemic attacks are “mini strokes” that produce stroke-like symptoms but no lasting damage. They are strong predictors of stroke. A person who’s had one or more TIAs is almost 10 times more likely to have a stroke than someone of the same age and sex who hasn’t.
High red blood cell count. An increase in the red blood cell count is a risk factor for stroke. Excess of red blood cells thicken the blood and make clots more likely to form.
Cerebral aneurysms. Aneurysms are blood-filled pouches that balloon out from weak spots in the artery wall. They’re often caused or aggravated by high blood pressure but can be congenital. Aneurysms aren’t always dangerous, but if one bursts in the brain, a haemorrhagic stroke results. More common cause of stroke in those under 40 years.
Drug abuse. Intravenous drug users are at risk of stroke from cerebral embolisms. Cocaine use has been closely related to strokes and heart attacks. Some have been fatal even in first-time cocaine users.