Transient ischaemic attack

Also called warning stroke or ministroke

Transient ischaemic attack (TIA) is the same as a stroke, except that the signs last for a short amount of time. TIA is regarded as a medical emergency because there is a high risk that stroke will occur within the next 48 hours.

Because of this, a TIA is often called a warning stroke or mini-stroke. It shouldn’t be ignored. If treated quickly, the risk of stroke can be greatly reduced. 

TIA is a medical emergency. Call 111 immediately if you develop any of the following symptoms or warning signs.
  • Weakness, usually on one side of the face, arm or leg
  • Numbness or pins and needles in the face, arm or leg on one side of the body
  • Slurring of speech or difficulty in finding words can also occur
  • Part or complete loss of vision or blindness in one or both eyes
  • Dizziness or loss of balance or coordination

These symptoms usually come on suddenly, and lasts from seconds, or minutes to hours. It does not usually last longer than 24 hours.

What causes TIA?

TIA is when blood supply to a part of the brain is temporarily blocked. In most cases, this is caused by a blood clot which develops because of plaque.  

Plaque is a buildup of cholesterol-containing fatty deposits in a blood vessel. It can decrease the blood flow through the blood vessel and lead to the development of a clot.

If the blood flow to a blood vessel that supplies your brain or eye is blocked, then the symptoms of TIA occur. The blockage is temporary because the clot either dissolves or moves. After this the blood supply to the brain returns to normal and the signs disappear. Most TIA lasts less than 5 minutes. 

You may have more than one TIA, and the signs and symptoms of each may be similar or different depending on which area of the brain is involved.

Who is at risk of having TIA?

The factors that increase your chances of having a TIA are the same as those that increase your risk of stroke. 

Risk factors for TIA & stroke

Check your risk with the  Stroke Riskometer app developed by the Auckland University of Technology, 2015.

What are the symptoms of a TIA?

The symptoms of a TIA are the same as those of a stroke, but unlike a stroke they only last for a few minutes or hours.

Like a stroke, the signs and symptoms of a TIA usually begin suddenly.

The main symptoms can be remembered with the word FAST: Face-Arms-Speech-Time.

  • Face – has the face dropped on one side? Is one side of the smile droopy?
  • Arms – can both arms be lifted about the head and kept there, or is one arm weak or numb?
  • Speech – is speech slurred or garbled? 
  • Time – lost time is lost brain. Dial 111 immediately if you notice any of these signs or symptoms.

It is not possible to tell the difference between TIA and stroke in the early stages, so urgent medical help must be sort if any of the signs and symptoms above are noticed. 

Even if the symptoms have stopped before help arrives, you should still go to hospital for assessment. TIA is a warning sign that stroke is going to happen in the near future. Getting checked out gives your medical team the chance to determine the best way to lower the risk of this happening. 

If you think you may have had a TIA previously and didn't get it checked out, make an appointment to see your doctor urgently. They will assess whether you need to go to hospital for further assessment. 

How is a TIA treated? 

Although the symptoms of a TIA go away in a few minutes or hours, you will 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. Treatment usually includes medication to reduce the risk of blood clots forming such as:

Medication Description
Anti-platelet treatment
  • These work by preventing certain types of blood cells (called platelets) from sticking together to make blood clot. This makes blood 'thinner' and allows it to flow more easily.
  • Examples include:
    • aspirin
    • clopidogrel
    • dipyridamole
Anticoagulant treatment
  • If you have irregular heart beat, such as atrial fibrillation, you may be at risk of TIA because a clot can enter your blood stream from your heart.
  • In  this case, you may prescribed an anticoagulant to prevent your blood from clotting.
  • Examples include:
    • warfarin 
    • dabigatran
Medication to lower your blood pressure (antihypertensives)
  • Raised blood pressure increases your chance of TIA greatly, and lowering blood pressure decreases the likelihood of stroke following TIA.
Medication to lower your cholesterol (statins)
  • Raised cholesterol increases your chance of TIA, and contributes to the formation of fatty deposits in the blood vessels. Lowering cholesterol decreases the likelihood of stroke following TIA.

Learn more

TIA or ministroke Stroke Foundation NZ
Transient ischaemic attack NHS Choices UK
Transient ischaemic attack – Explained Watch, Learn, Live: Interactive Cardiovascular Library – American Heart Association

Credits: Images from the Stroke Foundation's brochure 'What is a TIA'.