A stroke is a serious medical condition that occurs when the blood supply to the brain is disturbed.

Like all organs, to function properly, our brain needs the oxygen and nutrients that are provided by our blood. If the supply of blood is restricted, or stopped, brain cells will begin to die. This can lead to brain damage and possibly death.

Strokes are a medical emergency and prompt treatment is essential because the sooner a person receives treatment for a stroke, the less damage is likely to result.

Types of stroke

There are two main causes of strokes:

• ischaemic - where the blood supply is stopped due to a blood clot, and
• haemorrhagic - where the blood vessels supplying the brain burst and cause brain damage.

Ischaemic strokes are the most common type of stroke, accounting for around 70% of all cases.

There is also a related condition known as a transient ischaemic attack (TIA), where the supply of blood to the brain is temporarily interrupted, causing a sort of 'mini-stroke'. TIAs should be treated very seriously as they are often a warning sign that a more serious stroke is to come.

Who is at risk from stroke?

Strokes are a major health problem and are the third largest cause of death. The brain damage that is caused by strokes means that they are the largest cause of adult disability.

People who are over 65 years of age are most at risk from having strokes, but they can affect people of any age, including children.

Those of Afro-Caribbean origin are at increased risk of having a stroke, and the number of people affected by the condition is higher among this ethnic group than any other. This is because people of Afro-Caribbean origin have a genetic predisposition (a natural tendency) to developing diabetes and heart disease, which are two conditions that can cause strokes.

Smoking, obesity, poor diet and excessive alcohol consumption are also associated risk factors for having a stroke. Also, conditions that affect the circulation of the blood, such as diabetes, or hypertension (high blood pressure) increase your risk of having a stroke.

Strokes can be treated and prevented

Strokes can usually be successfully treated and they can also be prevented. Following a healthy diet, getting regular exercise, drinking alcohol in moderation, and not smoking, will dramatically reduce your risk of having a stroke.

Strokes can be treated using a combination of surgery and medicines. However, many people will require a long period of rehabilitation after a stroke, and not all will recover fully.