Around 100,000 people in England and Wales have a first stroke each year - one every five minutes. Anyone can have a stroke, including babies and children, but the vast majority - nine out of 10 - affect people over 55. However, approximately 10,000 strokes a year occur in people under the age of 55, and some 300,000 people are living with disabilities caused by a stroke. It is estimated that around a third of people who have a stroke will die within the first year. Another third will make a good recovery, while the final third will be left with moderate to severe disabilities.

What is a stroke?

Stroke is the term used to describe the effects of an interruption of the blood supply to a localised area of the brain. The brain is the nerve centre of the body, controlling everything we do or think, as well as controlling automatic functions like breathing. In order to work, the brain needs a constant supply of oxygen and nutrients. These are carried to the brain by blood through the arteries. If part of the brain is deprived of blood, brain cells are damaged or die. This causes a number of different effects, depending on the part of the brain affected and the amount of damage to brain tissue.

What are the symptoms?

Stroke is well named because, for most people, symptoms come on literally at a stroke. The key symptoms include sudden numbness, weakness or paralysis on one side of the body, signs of this may be a drooping arm, leg or eyelid, or a dribbling mouth. Also sudden slurred speech or difficulty finding words or understanding speech: sudden blurring, disturbance or loss of vision, especially in one eye: dizziness, confusion, unsteadiness and/or a severe headache.

What is a TIA?

A Transient Ischaemic Attack (TIA), sometimes called a 'mini-stroke', occurs when the brain's blood supply is briefly interrupted. Unlike a full-blown stroke, the symptoms of a TIA - which are very similar to a full stroke - last under 24 hours and afterwards there is full recovery. A TIA is an indication that part of the brain is not getting enough blood and that there is a risk of a stroke occurring. A TIA should never be ignored and should be reported to a medical professional as soon as possible.

What causes a stroke?

There are two main types of stroke, and each has different causes. The first type, an ischaemic stroke, occurs when a blood clot blocks an artery serving the brain, disrupting blood supply. Very often an ischaemic stroke is the end result of a build up of cholesterol and other debris in the arteries (atherosclerosis) over many years. An ischaemic stroke may be due to:

A cerebral thrombosis, in which a blood clot (thrombus) forms in a main artery leading to the brain, cutting off blood supply.

A cerebral embolism, in which a blood clot forms in a blood vessel elsewhere in the body, for instance in the neck or the heart, and is carried in the bloodstream to the brain.

A lacunar stroke, in which the blockage is in the small blood vessels deep within the brain.

The second main type of stroke is a haemorrhagic stroke, when a blood vessel in or around the brain bursts, causing a bleed or haemorrhage. Long-standing, untreated high blood pressure places a strain on the artery walls, increasing their risk of bursting and bleeding.

A haemorrhagic stroke may be due to:

An intracerebral haemorrhage, in which a blood vessel bursts within the brain itself. A subarachnoid haemorrhage, in which a blood vessel on the surface of the brain bleeds into the area between the brain and the skull, known as the subarachnoid space.

Who is at risk?

A number of different factors increase the risk of stroke, including:o Untreated high blood pressure (hypertension). This damages the walls of the arteries.

Atrial fibrillation. This type of irregular heartbeat increases the risk of blood clots forming in the heart, which may then dislodge and travel to the brain.

A previous TIA. Around one in five people who have a first full stroke have had one or more previous TIAs.

Diabetes. People with diabetes are more likely to have high blood pressure and atherosclerosis, and so are at much higher risk of stroke.

Smoking. This has a number of adverse effects on the arteries and is linked to higher blood pressure.

Regular heavy drinking. Over time this raises blood pressure, while an alcohol binge can raise blood pressure to dangerously high levels and may trigger a burst blood vessel in the brain.

Certain types of combined oral contraceptive pill. These can make the blood stickier and more likely to clot. They may also raise blood pressure.

Diet. A diet high in salt is linked to high blood pressure, while a diet high in fatty, sugary foods is linked to furring and narrowing of the arteries.

Age. Strokes are more common in people over 55, and the incidence continues to rise with age. This may be because atherosclerosis takes a long time to develop and arteries become less elastic with age, increasing the risk of high blood pressure.

Gender. Men are at a higher risk of stroke than women, especially under the age of 65.

Family history. Having a close relative with stroke increases the risk, possibly because factors such as high blood pressure and diabetes tend to run in families.

Ethnic background. Asians, Africans or African-Caribbeans are at greater risk. The reasons are not yet fully understood but are partly linked to factors like diabetes, which is more common in Asians, and high blood pressure, which is more common in people of African descent.

What are the effects?

The effects of a stroke vary enormously, and depend on which part of the brain is damaged and the extent of that damage. For some, the effects are relatively minor and short lived; others are left with more severe, long-term disabilities. Common problems include:

Weakness or paralysis (hemiplegia) on one side of the body. Because the right side of the brain controls the left side of the body (and vice versa), hemiplegia occurs on the opposite side of the body to where the stroke occurred.

Speech and language difficulties. Many people experience problems with speaking, understanding, reading and writing. These problems can range from temporary difficulty in finding words, to a complete inability to communicate. Most people who experience speech and language problems have damage in the left side of the brain, which is responsible for language, reading, writing and numbers.

Difficulties in perception. There may be difficulty recognising familiar objects or knowing how to use them. There may also be problems with abstract concepts such as telling the time. Although vision may not be affected directly it may be difficult for the brain to interpret what the eyes see.

Cognitive problems. A stroke often causes problems with mental processes such as thinking, learning, concentrating, remembering, decision making, reasoning and planning.

Fatigue. Tiredness is very common after stroke, though the causes for this are unclear.

Mood swings. As with any serious illness, emotional ups and downs may be experienced following a stroke. Depression, anger, low self-esteem and loss of confidence are also common. Sometimes people experience difficulties in controlling their emotions and may cry, swear or laugh at inappropriate times.

How is it diagnosed?

A number of investigations can help identify the type of stroke that has occurred and the best treatment options. The precise tests will differ from person to person, but common ones include:

blood pressure measurement
blood tests to check blood sugar, clotting and cholesterol levels
chest X-ray to check for heart or chest problems
an electrocardiogram (ECG) to measure the rhythm and activity of the heart

an echocardiogram, a type of heart scan, to check for heart problems o brain scans to determine the type of stroke and to look for signs of damage o an ultrasound scan of the carotid arteries to check blood flow to the brain.

How is stroke treated?

Depending on the severity of the stroke, the person will either be admitted to hospital or receive treatment at home. Wherever treatment takes place, in the early days the aim is to stabilise the condition, control blood pressure and prevent complications. The doctor may prescribe drugs designed to prevent a further stroke and to treat any underlying conditions, such as high blood pressure or high cholesterol levels. There are literally hundreds of drugs available and the ones prescribed will depend on the patient's specific needs. Many people who have had a stroke are prescribed aspirin because it helps make blood less sticky and less likely to clot.

What is rehabilitation?

Once the patient is stable the medical team will work out an individual rehabilitation programme designed to help them regain as much independence as possible. The purpose of rehabilitation is to help people relearn skills they have lost, to learn new skills and find ways to manage any permanent disabilities they may have been left with. A rehabilitation programme is likely to include methods designed to help with posture, balance and movement, together with any special help needed with specific difficulties such as speech and language.

Many different professionals may be involved in this, but a patient's motivation and efforts are equally important. Key experts likely to be encountered include doctors and nurses (specialist stroke nurses or community nurses) to oversee medical management; physiotherapists to help with problems of posture and movement; occupational therapists to help with everyday activities at home, leisure and work; speech and language therapists to help with communication problems; and clinical psychologists to help with problems affecting mental processes and emotions. A number of other professionals may also be involved, including social workers, dieticians, chiropodists and ophthalmologists (eye specialists).

How long will it take to recover?

The brain is a remarkable organ and is capable of adapting to change. In the weeks and months following a stroke many partially-damaged cells recover and start to work again. Meanwhile, other unaffected parts of the brain take over jobs that were previously performed by the brain cells which were destroyed. The length of time it takes to recover varies widely from person to person. It is common to have an initial spurt of recovery in the first few weeks after the stroke as the brain settles down. As a rule, a majority of recovery often takes place during the first year to 18 months, but many people continue to improve over a much longer period.

For more information The Stroke Association publishes material covering many aspects of stroke and its management.

To receive a publications order form contact your local Stroke Association office or write to: The Stroke Association, Northampton Resource Centre, Charles House, 61-69 Derngate, Northampton NN1 1HD. The order form can also be obtained from the stroke Association website.