What is a stroke?

A stroke occurs when the blood supply to the brain is interrupted, depriving the brain of oxygen. As a result, some of the brain cells die and others are damaged. This means that the area of the body normally controlled by the damaged part of the brain will not be able to function properly.

A stroke is also known as a cerebrovascular accident.

What causes a stroke?

Ischaemic strokes

The majority of strokes are caused by a sudden blockage in the blood vessels (arteries) supplying the brain, by a blood clot (thrombus). This is called an ischaemic stroke. The clot may actually form in an artery supplying blood to the brain. Clots can also form elsewhere in the body and then travel via the blood vessels to the brain, where they lodge in an artery and cut off the blood supply. This form of clot is called an embolism.

Various factors can increase risk of a clot developing – these include high blood pressure and a condition called atherosclerosis – which causes hardening and narrowing of the arteries.

Haemorrhagic strokes

Some strokes are caused by the sudden bursting (haemorrhaging) of an artery in the brain, leading to bleeding inside the brain. This type of stroke is much less common.

What is a mini-stroke (TIA)?

A “mini-stroke” or transient ischaemic attack (TIA) is a brief loss of blood supply to the brain, causing the person affected to experience brief symptoms of stroke (see below). The blood supply is quickly restored and symptoms of the stroke completely disappear – normally within 24 hours.

A TIA doesn’t usually cause any permanent brain damage or disability; however it is a warning sign that you may be at serious risk of a major stroke, so you must seek medical attention if you think you have had a TIA.

What are the symptoms of stroke?

Different parts of the brain control different functions in the body, such as speaking, memory, swallowing and moving. The symptoms of a stroke therefore depend on which part of the brain is affected and the extent of the damage. Some of the following effects may be experienced:

If you, or someone else is having a stroke, it is important to get emergency medical treatment as soon as possible, as the sooner treatment is given, the less risk there will be of long-term damage. If symptoms of a stroke seem to be occurring, contact your doctor or phone for an ambulance immediately.

Who is at risk of having a stroke?

The following factors can increase the risk of a stroke:

Can I prevent stroke?

Some factors – such as age and family history cannot be changed. However, you can greatly reduce your risk of having a stroke by making some lifestyle changes – such as giving up smoking, losing any excess weight, getting regular physical exercise, keeping alcohol intake to within recommended limits, eating more fruit and vegetables and eating less salt and fatty foods.

It is also important to get regular blood pressure checks and treatment if necessary for high blood pressure.

How is stroke diagnosed?

A doctor will carry out a physical examination to check your symptoms, such as co-ordination, memory, speech and thinking. Other tests, such as a CT or MRI scan may be carried out to obtain images of your brain, in order to see which areas have been affected and the extent of the damage.

How is a stroke treated?

If your stroke has been caused by a clot, you may be given a drug to break down the clot and reduce the damage to your brain. However, this drug is only suitable for certain patients, and is only useful if given within 3 hours of the stroke occurring.

You may also be given drugs to prevent the blood from clotting and to ‘thin’ the blood. An common example of this type of drug is aspirin. If you have high blood pressure or high cholesterol, you will also be given drugs to control these conditions, and reduce your risk of another stroke occurring.


Once you have begun to recover from your stroke, the main focus of your treatment will be on rehabilitation. The aim of rehabilitation is to resolve any speech problems and restore any lost movement or sensation you may have. Participating in a good rehabilitation programme can greatly help you recover from a stroke.

A rehabilitation programme will be specifically designed for you, depending on your individual needs – and may involve physiotherapists, speech therapists, occupational therapists, nurses and doctors.

What is the outlook?

While there is currently no known cure for a stroke, about half of all people recover completely from their first stroke through an effective rehabilitation programme. Unfortunately, many people who have had a stroke may suffer some permanent damage and require some level of assistance. However, in many cases other parts of the brain compensate for the damaged area and rehabilitation can help to restore much of the lost movement or sensation. The rate of recovery is different for every person.

There are various support groups in Ireland that offer services and support for people with stroke, including:

Reviewed: October 13, 2006