Transient Ischaemic Attack (TIA or Mini-Stroke): Symptoms, Causes, and Treatment

A transient ischaemic attack, or TIA, often called a mini-stroke, happens when the blood supply to part of the brain, spinal cord or eye is briefly cut off, usually by a small blood clot. It causes the same sudden symptoms as a stroke, such as drooping on one side of the face, weakness or numbness in an arm or leg, and slurred or muddled speech, but the symptoms go away completely, usually within an hour and always within 24 hours, because no lasting damage is done. A TIA is still a medical emergency. Anyone with stroke or TIA symptoms should call the emergency services straight away, even if the symptoms have already stopped, because a TIA is a strong warning that a disabling stroke may follow soon: the risk is highest in the first 2 days, and without treatment around 1 in 5 people have a stroke within 3 months. Fast specialist assessment and treatment, usually with a blood-thinning tablet, a statin, blood-pressure control and treatment of any irregular heart rhythm, cut the risk of a later stroke by around 80 percent. Guidance from the NHS in the United Kingdom, US clinical guidelines, and the Stroke Foundation in Australia all say the same: treat a TIA as an emergency and get seen the same day.

In plain words

A transient ischaemic attack, or TIA, is often called a mini-stroke. It happens when blood flow to part of the brain is blocked for a short time. It causes the same signs as a stroke. The face may droop on one side. An arm may go weak. Speech may be slurred. But the signs go away, often within an hour. A TIA is still an emergency. Call for an ambulance even if the signs have stopped. A TIA is a warning. A full stroke can follow within days. About 1 in 5 people have a stroke within 3 months if a TIA is not treated. Fast care and daily medicine cut that risk by a lot. You will likely need a blood-thinning tablet, a cholesterol tablet, and blood pressure treatment. You may need a neck scan and, if an artery is narrowed, a small operation. Learn the FAST test. Face, Arms, Speech, Time. Call 911 in the US, 999 in the UK, or 000 in Australia.

What is Transient Ischaemic Attack (TIA or Mini-Stroke): Symptoms, Causes, and Treatment?

Symptoms

Early symptoms

Symptoms that came on suddenly and then went away: The key feature of a TIA is that stroke-like symptoms appear over seconds and then clear completely, usually within a few minutes to an hour. Because they resolve, people often wait or ignore them; this is exactly when to seek emergency assessment. (1) (2) (3)
Weakness or numbness on one side of the body: A drooping face, a weak or heavy arm or leg, or numbness affecting one side, is the most common pattern. (1) (2)
Speech and language problems: Slurred speech, difficulty finding words, or trouble understanding what is said. (1) (2)
Sudden vision change: Temporary loss of sight in one eye, described as a curtain rising or falling, or loss of part of the field of view in both eyes. (2) (1)
Loss of balance or coordination: Sudden clumsiness of a hand, unsteadiness or difficulty walking, especially together with any of the symptoms above. (2) (1)

Serious or emergency symptoms

Sudden face drooping, arm weakness or speech difficulty (the FAST test): FAST stands for Face (has the face fallen on one side, can the person smile?), Arms (can they raise both arms and keep them up?), Speech (is speech slurred or muddled, can they understand you?), Time. Any one of these, coming on suddenly, may be a stroke or a TIA. Call the emergency services now: 911 in the United States, 999 in the United Kingdom, or 000 in Australia. Ask for an ambulance. Do this even if the symptoms are mild or have already gone away completely; a person who has had a TIA still needs to be assessed in hospital or by a specialist the same day. Note the time the symptoms started. (1) (3) (2)
Sudden numbness, vision loss, dizziness with other signs, severe headache or confusion: Other sudden stroke and TIA symptoms include numbness or weakness down one side, loss of vision in one eye (like a curtain coming down) or to one side, sudden severe unbalance or difficulty walking together with other signs, sudden confusion or trouble understanding, and a sudden severe headache with no known cause. Call the emergency services now (911 / 999 / 000). Isolated dizziness or fainting on its own is usually not a TIA, but if it comes with any FAST sign or the symptoms above, treat it as an emergency. (1) (2) (3)

Causes

Primary causes

A blood clot from a furred-up artery: The most common cause is a small clot that forms on a patch of fatty build-up (atherosclerosis) in an artery in the neck or head, then briefly lodges in a smaller brain artery before breaking up. Narrowing of the carotid artery in the neck is an important and treatable version of this. (2) (1)
A clot travelling from the heart: A clot can form in the heart and travel to the brain. The commonest reason is atrial fibrillation, an irregular heart rhythm that lets blood pool and clot in the upper heart chambers. (2) (1)
Disease of the brain's small vessels: Long-standing high blood pressure and diabetes damage the tiny arteries deep in the brain, which can briefly block and cause a TIA. (2)

Contributing factors

Atrial fibrillation and other heart problems: Atrial fibrillation is the single most important treatable cause. Other heart sources include recent heart attack, heart-valve disease and, rarely, a hole between the heart's chambers (patent foramen ovale) in younger people. (2) (1)
A tear in an artery wall (dissection): A split in the lining of a neck artery, sometimes after neck injury, heavy lifting or vigorous neck movement, can cause a TIA or stroke, particularly in younger adults. (2)
Blood and clotting disorders: Conditions that make the blood clot too easily, some autoimmune diseases, and rarely inflammation of the blood vessels, can cause a TIA. Sickle cell disease is a cause in children and young adults. (2)

Risk factors

High blood pressure

Raised blood pressure is the single most important and most treatable risk factor for TIA and stroke. (2) (1)

Irregular heart rhythm (atrial fibrillation)

Atrial fibrillation greatly increases the risk of a clot travelling to the brain. It is often silent and is looked for after a TIA. (2) (1)

Diabetes and high cholesterol

Both speed up furring of the arteries and raise TIA and stroke risk. (2) (1)

Smoking, excess alcohol and being overweight

Smoking roughly doubles stroke risk; heavy alcohol use and obesity add further risk. All are changeable. (1) (2)

Older age, a previous TIA or stroke, and family history

Risk rises with age, especially over 55, and is higher in people who have already had a TIA or stroke. People of South Asian, African or Caribbean background have a higher stroke risk, partly through higher rates of high blood pressure and diabetes. (1) (2)

Physical inactivity

Being inactive raises blood pressure, weight and diabetes risk, and so raises stroke risk. (2) (1)

Diagnosis

After a suspected TIA the aim is a fast, complete evaluation to find the cause and start prevention before a stroke happens. In the United Kingdom, anyone with a suspected TIA should be seen by a stroke specialist within 24 hours and given aspirin straight away unless there is a reason not to. A doctor checks the story of the symptoms, examines the nervous system, measures blood pressure in both arms and checks the heart rhythm. A brain scan is done, and an MRI scan with diffusion-weighted imaging is preferred because it can show a tiny stroke that a CT scan misses. An ultrasound of the neck arteries looks for carotid narrowing that could be operated on. The heart is checked with an ECG and often with several days of heart-rhythm monitoring to catch atrial fibrillation, and sometimes with an echocardiogram. Blood tests check for diabetes, cholesterol, and, in younger people, clotting problems. This urgent, same-day approach is shared by NHS and NICE guidance in the UK, US stroke guidelines, and the Stroke Foundation in Australia.

Brain scan (MRI with diffusion-weighted imaging, or CT)

Looks for a small stroke and rules out bleeding or another cause. MRI is more sensitive for tiny strokes. (2) (1)

Carotid ultrasound

Checks the neck arteries for narrowing. Significant narrowing on the same side as the symptoms may be treated with surgery or a stent. (2) (1)

ECG and prolonged heart-rhythm monitoring

Looks for atrial fibrillation, which changes treatment from an antiplatelet to an anticoagulant. It is often intermittent, so monitoring for days improves detection. (2) (1)

Blood tests, and sometimes an echocardiogram

Check blood sugar, cholesterol and, when relevant, clotting. An ultrasound of the heart looks for a source of clots. (2) (1)

Treatment

Medication options

Antiplatelet medicines (when the heart rhythm is normal)

Antiplatelet tablets make the blood less sticky and are the main treatment after a TIA that is not caused by atrial fibrillation. Guidelines advise starting aspirin immediately. For a higher-risk TIA, aspirin and clopidogrel are often taken together for the first 3 weeks (21 days) and then a single antiplatelet, usually clopidogrel or aspirin with dipyridamole, is continued long term. (2) (1)

Anticoagulant medicines (when atrial fibrillation is found)

If a TIA is caused by atrial fibrillation, an anticoagulant, such as apixaban, rivaroxaban, dabigatran or warfarin, is much more effective than an antiplatelet at preventing a stroke. It is usually started within a few days. (2) (1)

Statins and blood-pressure medicines

A high-intensity statin, such as atorvastatin, lowers cholesterol and stabilises the fatty patches in the arteries. Blood-pressure medicines, often started or increased after a TIA, are one of the most powerful ways to prevent a stroke. Diabetes is also treated to target. (2) (1)

Carotid surgery or stenting (for significant neck-artery narrowing)

If a scan shows narrowing of 50 to 99 percent in the carotid artery on the same side as the symptoms, an operation to clear it (carotid endarterectomy), or sometimes a stent, greatly reduces the risk of a future stroke. It is done as soon as possible, ideally within 2 weeks of the TIA. (2) (1)

Lifestyle and self-care

Control blood pressure: Keeping blood pressure in the target range your doctor sets is the most effective single thing you can do to prevent a stroke. Use a home monitor if advised, take medicines as prescribed, and reduce salt. (1) (2)
Stop smoking and limit alcohol: Stopping smoking lowers stroke risk quickly. Keep alcohol within recommended limits. Quit services can help; in Australia call Quitline on 13 7848. (1) (3)
Eat well, move more and manage weight: A diet rich in vegetables, fruit, wholegrains and fish, lower in salt and processed food, plus regular activity such as brisk walking most days, lowers blood pressure, cholesterol and diabetes risk. (1) (2)
Take every dose of your prevention medicines: The antiplatelet or anticoagulant, statin and blood-pressure tablets only work if taken regularly. Use a pill organiser or reminders, and ask about side effects rather than stopping. (2) (1)
Know the FAST signs and act fast next time: Make sure you and the people around you know the FAST signs and to call the emergency services immediately, without waiting to see if symptoms pass. (1) (3)
Check driving rules: There are usually rules about not driving for a period after a TIA, which vary by country and licence type. Ask your doctor or the driving authority before you drive again. (1)

Always discuss dosing and treatment changes with your own prescriber.

Possible complications

A full stroke, especially in the first days: A TIA is a warning. The risk of a stroke is highest in the first 48 hours and stays high for weeks. Without treatment, around 1 in 5 people have a stroke within 3 months of a TIA; the 90-day risk is roughly 5 percent even with usual care and much higher for untreated high-risk TIAs. This is why same-day assessment matters. (2) (1)
Heart attack and vascular death: The same artery disease that causes a TIA also affects the heart. Nearly 1 in 5 people have a stroke, heart attack or die from a vascular cause within the first year after a TIA if risk factors are not treated. (2)
Repeated TIAs: Some people have several TIAs before a stroke. Each one is an emergency and each is a chance to prevent the stroke. (1) (2)
The outlook (prognosis) with treatment: The prognosis is very different with fast treatment. A full prevention package, an antiplatelet or anticoagulant, a statin, blood-pressure control and lifestyle change, lowers the risk of a further stroke by around 80 percent. Living with a TIA means taking these medicines long term and keeping up regular reviews. (2) (1)

When to see a doctor

Routine follow-up

After you have been assessed for a TIA, keep every follow-up appointment, blood test and blood-pressure check, and see your doctor if you have side effects from the prevention medicines rather than stopping them. (1) (2)
See your doctor promptly if you notice a new irregular or racing heartbeat, or palpitations, as this could be atrial fibrillation that needs anticoagulation. (2) (1)
Ask your doctor when it is safe to drive again, as there are legal rules after a TIA that depend on your country and licence. (1)

Seek emergency care

Call the emergency services now, 911 in the United States, 999 in the United Kingdom or 000 in Australia, and ask for an ambulance if you or someone else has sudden face drooping, arm weakness, slurred or muddled speech, sudden numbness or vision loss, sudden severe unbalance, or sudden confusion. Do this even if the symptoms are mild or have already gone away completely, and note the time they started. (1) (3) (2)

Frequently asked questions

What is the difference between a TIA and a stroke?

The symptoms are the same, but in a TIA the blockage clears before it causes lasting damage, so the symptoms go away completely, usually within an hour. In a stroke the blockage or bleed damages brain tissue and symptoms persist. You cannot tell which is which at the time, so both are treated as an emergency. (1) (2) (3)

If the symptoms have gone, do I still need to go to hospital?

Yes. A TIA is a warning that a full stroke may be coming, and the risk is highest in the first 2 days. Call the emergency services even if you feel completely back to normal; you need a specialist assessment the same day and treatment started quickly. (1) (3) (2)

What is the FAST test?

FAST stands for Face (has the face dropped on one side?), Arms (can the person raise both arms and keep them up?), Speech (is it slurred or muddled?), Time (call the emergency services immediately). It is the quick way to recognise a stroke or TIA. (1) (3)

How high is my risk of a stroke after a TIA?

Without treatment, around 1 in 5 people have a stroke within 3 months of a TIA, and the risk is highest in the first 48 hours. With fast assessment and a full prevention package the risk falls by around 80 percent, which is why a TIA must be treated urgently. (2) (1)

What treatment will I be given?

Usually a blood-thinning tablet (an antiplatelet such as aspirin then clopidogrel if the heart rhythm is normal, or an anticoagulant if atrial fibrillation is found), a high-intensity statin, and blood-pressure treatment. If a neck-artery is significantly narrowed on the side of the symptoms, an operation or stent may be advised, ideally within 2 weeks. (2) (1)

Is dizziness or fainting a mini-stroke?

Usually not. Dizziness on its own, or a simple faint, is rarely a TIA. But sudden dizziness or unbalance together with any FAST sign, numbness, vision loss, double vision or difficulty speaking should be treated as an emergency. (2) (1)

Can I drive after a TIA?

There are usually rules about a period of not driving after a TIA, and they depend on your country and the type of licence. Ask your doctor or the driving authority before you drive again. (1)

Will I have more TIAs?

Some people have more than one TIA before a stroke, and repeated TIAs are a sign of high risk. Each one is an emergency and each is a chance to prevent a stroke by getting assessed and treated quickly. (1) (2)

Can a TIA cause lasting damage?

By definition a TIA leaves no lasting damage on a scan, though some people notice brief tiredness or mild memory or mood effects for a short time. The danger of a TIA is the stroke it warns of, not the TIA itself. (2) (1)