A transient ischemic attack (TIA) or a "mini stroke" is caused by a temporary disruption in the blood supply to part of the brain.
The disruption in blood supply results in a lack of oxygen to the brain. This can cause sudden symptoms similar to a stroke, such as speech and visual disturbance, and numbness or weakness in the face, arms and legs.
However, a TIA doesn't last as long as a stroke. The effects often only last for a few minutes or hours and fully resolve within 24 hours.
The main symptoms of a TIA can be remembered with the word FAST: Face-Arms-Speech-Time. Even if the symptoms disappear while you're waiting for the ambulance to arrive, an assessment in hospital should still be carried out.
A TIA is a warning that you may be at risk of having a full stroke in the near future, and an assessment can help doctors to determine the best way to reduce the chances of this happening.
If you think you may have had a TIA previously, but the symptoms have passed and you didn't seek medical advice at the time, make an urgent appointment with your GP. They can determine whether to refer you for a hospital assessment.
During a TIA, one of the blood vessels that supply your brain with oxygen-rich blood becomes blocked.
This blockage is usually caused by a blood clot that has formed elsewhere in your body and travelled to the blood vessels supplying the brain, although it can also be caused by pieces of fatty material or air bubbles.
Certain things can increase your chances of having a TIA, including:
People over 60 years of age, and people of Asian, African or Caribbean descent are also at a higher risk of having a TIA.
Although the symptoms of a TIA resolve in a few minutes or hours, you'll need treatment to help prevent another TIA or a full stroke happening in the future.
Your treatment will depend on your individual circumstances, such as your age and medical history.
You're likely to be given advice about lifestyle changes you can make to reduce your stroke risk, in addition to being offered medication to treat the underlying cause of your TIA.
In some cases, surgery may be needed to unblock the carotid arteries (the main blood vessels that supply the brain with blood).
A TIA is often a sign that another one may follow and you're at a high risk of having a full, life-threatening stroke in the near future.
Regardless of whether you've had a TIA or stroke in the past, there are a number of ways you can lower your risk of having either in the future. These include: