What causes transient ischaemic attack?

A small clot can briefly block an artery supplying the brain and then move or dissolve, so weakness, numbness, speech trouble, or vision loss may improve. An irregular heart rhythm such as atrial fibrillation can allow clots to form in the heart. Hypertension can damage and narrow artery walls, increasing the chance of clot-related problems.

Symptoms that disappear still need urgent assessment. A TIA is a warning that another interruption may occur, and early evaluation can identify treatable causes such as an abnormal rhythm, high blood pressure, or narrowing in a blood vessel.

If facial drooping, arm weakness, speech difficulty, sudden vision change, or loss of balance starts, note the time and call emergency services immediately, even if it resolves. Do not drive yourself. Keep a list of medicines and medical conditions available for the emergency team.

Treat any possible TIA or stroke symptoms as an emergency. Do not wait to see whether they settle. Emergency clinicians may arrange brain and blood-vessel imaging, heart-rhythm checks, blood-pressure assessment, and blood tests to find the cause and reduce future risk.

Ask what tests are needed to look for atrial fibrillation, hypertension, or artery narrowing, and how each result changes treatment. Check which medicines, blood-pressure targets, activity changes, and follow-up appointments apply to you.