Transient ischaemic attack (TIA): symptoms, causes and what to do

The signs and symptoms of a TIA are the same as those of a stroke and usually begin suddenly. The NHS uses the FAST checklist. Face: the face may have dropped on one side, the person may not be able to smile, or their mouth or eye may have dropped. Arms: they may not be able to lift both arms and keep them raised because of weakness or numbness in one arm. Speech: it may be slurred or garbled, or the person may not be able to talk at all, or may not understand what you are saying. Time: call 999 immediately if you see any of these.

NHS inform adds that a person might not have all of these symptoms, and that TIAs sometimes cause other symptoms that appear suddenly, usually over a few seconds.

• Complete paralysis of one side of the body.

• Sudden loss or blurring of vision.

• Dizziness and confusion.

• Difficulty understanding what others are saying.

• Problems with balance and co-ordination.

Call 999. The NHS says that in the early stages it is not possible to tell whether you are having a TIA or a full stroke, so you need an ambulance. Even if the symptoms disappear while you are waiting, you still need to be assessed in hospital.

The Stroke Association says not to wait to see if symptoms pass. If you did not get help at the time, get an urgent appointment with your GP or go to an NHS urgent treatment centre so you can be referred for an assessment at hospital. The NHS gives similar advice if you think you may have had a TIA in the past: make an urgent appointment with a GP, who can decide whether to refer you.

NHS inform says not to drive if you suspect you have had a stroke or TIA.

The NHS says that during a TIA one of the blood vessels that supply the brain with oxygen-rich blood becomes blocked. This is usually caused by a blood clot that has formed elsewhere in the body and travelled to the brain, although fatty material or air bubbles can also be responsible. NHS inform adds that atrial fibrillation, a type of irregular heartbeat, can create clots that escape from the heart and become stuck in the blood vessels supplying the brain.

The NHS lists these as things that can increase your chances of having a TIA: smoking, high blood pressure, obesity, high cholesterol, regularly drinking an excessive amount of alcohol, atrial fibrillation and diabetes. People over 55 and people of Asian, African or Caribbean descent are also at higher risk.

NHS inform lists risk factors you cannot change as age, family history of stroke in a close relative, ethnicity (south Asian, African or Caribbean people have a higher risk of stroke, partly because rates of diabetes and high blood pressure are higher), and a medical history of stroke, TIA or heart attack.

The symptoms are the same at the start. NHS inform explains that in a TIA the blockage resolves before any significant damage is done, while a full stroke disrupts the blood flow to the brain for much longer, leading to more severe damage and longer-term problems. The Stroke Association says that when the blockage moves away or dissolves, the blood supply returns and the symptoms stop.

Because it is impossible to tell the two apart in the early stages, they are treated in the same way: call 999.

The NHS, NHS inform and the Stroke Association all say the effects of a TIA last from a few minutes to a few hours and fully resolve within 24 hours. If symptoms last longer or do not clear, it should be treated as a stroke, which is a further reason to phone 999 rather than wait.

The risk after a TIA does not end when the symptoms do. The Stroke Association says the risk of a stroke is greatest in the first days and weeks, and NHS inform says the risk of another TIA or stroke is highest in the days after, so it is important to start medication as soon as you are advised to.

NHS inform explains that TIAs are often over quickly, so you may have no symptoms by the time you are seen. It is therefore important to describe what you felt and how long it lasted, which helps rule out other conditions. A neurological examination checks strength, sensation and co-ordination. If a TIA is suspected, medication to reduce the risk of another event should be started without waiting for test results.

Further tests are chosen to find the cause. They are not identical for everyone, and NHS inform notes that a brain scan is not always necessary.

The symptoms stop on their own, but NHS inform says you will need treatment to reduce the risk of another TIA or a full stroke. The NICE guideline summary says people should have their symptoms spotted quickly and a specialist see them within 24 hours, be offered the right scans and tests, and have aspirin offered straightaway after a TIA to help prevent a stroke.

NHS inform says a combination of treatments is usually recommended, which may include antiplatelets such as aspirin and clopidogrel, anticoagulants such as apixaban, edoxaban, rivaroxaban, dabigatran or warfarin, medication to lower blood pressure, and statins to lower cholesterol. It says antiplatelet medication needs to be taken immediately, while others may be started later and usually need to be taken long term. Do not start or stop any of these on your own.

In some cases the NHS says a carotid endarterectomy may be needed. This is an operation to remove part of the lining of the carotid artery and any blockage in it, which NHS inform says can reduce the risk of a stroke or another TIA.

The NHS says that a TIA is often a sign that another one may follow and that you are at high risk of a full, life-threatening stroke in the near future. Whether or not you have had a TIA or stroke before, there are several ways to lower your risk.

• Maintain a healthy weight.

• Eat a healthy, balanced diet (NHS inform suggests low-fat, low-salt and high-fibre, with plenty of fruit, vegetables and whole grains).

• Exercise regularly, which can help lower cholesterol and keep blood pressure at a healthy level.

• Limit alcohol.

• Stop smoking if you smoke.

• Take any prescribed medication, including anticoagulants if you have atrial fibrillation.

The emergency part of a TIA is an NHS matter. Ambulance, emergency department and rapid-access TIA or stroke services exist precisely because speed matters, and a private appointment booked for next week is not a substitute for being seen within 24 hours.

Once the acute phase has passed, some people choose to see a private neurologist or cardiologist for a second opinion, extra heart-rhythm monitoring or discussion of long-term prevention. That is a personal choice made after the urgent assessment, not instead of it. Your GP stays central to blood pressure, cholesterol and medicine reviews either way.