A stroke is a serious medical condition that occurs when the blood supply to part of the brain is cut off.
Like all organs, the brain needs the oxygen and nutrients provided by blood to function properly. If the supply of blood is restricted or stopped, brain cells 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 happen.
Types of stroke
There are two main causes of strokes:
ischaemic (accounting for over 80% of all cases): the blood supply is stopped due to a blood clot
haemorrhagic: a weakened blood vessel supplying the brain bursts and causes brain damage
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 'mini-stroke'. TIAs should be treated seriously as they are often a warning sign that a stroke is coming.
Who is at risk from stroke?
In England, strokes are a major health problem. Every year over 150,000 people have a stroke and it is the third largest cause of death, after heart disease and cancer. The brain damage caused by strokes means that they are the largest cause of adult disability in the UK.
People who are over 65 years of age are most at risk from having strokes, although 25% of strokes occur in people who are under 65. It is also possible for children to have strokes.
If you are south Asian, African or Caribbean, your risk of stroke is higher. This is partly because of a predisposition (a natural tendency) to developing diabetes and heart disease, which are two conditions that can cause strokes.
Smoking, being overweight, lack of exercise and a poor diet are also risk factors for stroke. Also, conditions that affect the circulation of the blood, such as high blood pressure, high cholesterol, atrial fibrillation (an irregular heartbeat) and diabetes, increase your risk of having a stroke.
Strokes can be treated and prevented
Strokes can usually be successfully treated and also prevented. Eating a healthy diet, taking regular exercise, drinking alcohol in moderation and not smoking will dramatically reduce your risk of having a stroke. Lowering high blood pressure and cholesterol levels with medication also lowers the risk of stroke substantially.
See the prevention section for more information about reducing the risk of having a stroke.
Strokes can be treated using a combination of medicines and, in some cases, surgery.
However, many people will require a long period of rehabilitation after a stroke and not all will recover fully.
Warning Signs of Stroke:
A stroke is a medical emergency
If you think you are having a stroke, dial 999 immediately. Limiting the damage from a stroke is important to your chances of recovery.
Recognising the signs and symptoms of a stroke
The signs and symptoms of a stroke vary from person to person but they usually begin suddenly. As different parts of your brain control different parts of your body, your symptoms will depend upon the part of your brain that has been affected and the extent of the damage.
The main stroke symptoms can be remembered with the word FAST: Face-Arms-Speech-Time.
· Face: the face may have dropped on one side, the person may not be able to smile or their mouth or eye may have drooped
· Arms: the person with suspected stroke may not be able to lift one or both arms and keep them there because of arm weakness or numbness
· Speech: their speech may be slurred or garbled, or the person may not be able to talk at all despite appearing to be awake
· Time: it is time to dial 999 immediately if you see any of these signs or symptoms
Symptoms in the FAST test identify about nine out of 10 strokes.
Other signs and symptoms may include:
· numbness or weakness resulting in complete paralysis of one side of the body
· sudden loss of vision
· communication problems, difficulty talking and understanding what others are saying
· problems with balance and coordination
· difficulty swallowing
· sudden and severe headache, unlike any the person has had before, especially if associated with neck stiffness
· blacking out (in severe cases)