Transient Ischemic Attack (TIA)

A TIA is a temporary blockage of blood flow to the brain.

Since it doesn't cause permanent damage, it might seem like no big deal.

But ignoring it is a big mistake. That's because a TIA may signal a full-blown stroke ahead.

TIAs are often labeled "mini-strokes," because they can be relatively benign in terms of immediate consequences. But the term "warning stroke" is more appropriate for these temporary episodes, because they can indicate the likelihood of a coming stroke.

Like most strokes, TIAs are caused by a clot or blockage in the brain. TIAs should be taken very seriously. If you suspect a TIA or stroke of kind, be sure to call 9-1-1. Know the warning signs.

Blockage is short-term or temporary during a TIA or warning stroke. The clot may dissolve on it its own or get dislodged so that it stops causing the symptoms.

Temporary symptoms may occur. A third of U.S. adults have had symptoms consistent with a TIA. The symptoms are similar to an ischemic stroke, but TIA symptoms usually last less than five minutes with an average of about a minute. When a TIA is over, that particular blockage usually causes no permanent injury to the brain.

A TIA is an important warning sign. Warning strokes can signal a problem that may lead to disability, further strokes or even death.

  • The body resolves the blockage. The blockage causing the TIA may get pushed "downstream" or may be broken up by natural clot-dissolvers (called anticoagulants) in the blood, so the blockage is not in place long enough to cause any lasting damage to the brain.
  • Blood flow is restored quickly. Without blood flow, brain tissue can be injured. The severity of any blockage-related stroke is determined by how long the tissue was without blood flow and the location of the injury in the brain. When an episode is diagnosed as a TIA, it's because there is evidence of a blockage but no lasting damage has happened yet.
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Warning strokes are often followed by more severe strokes. Approximately 15% of all strokes are heralded by a TIA.

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People who have severe strokes often report having earlier warning strokes. Among patients who are treated for a blockage-related stroke (called an ischemic stroke), between 7 and 40% report experiencing a TIA first.

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Warning strokes are often followed by more severe strokes. About a third of the people who have a TIA go on to have a more severe stroke within a year.

  • All stroke survivors should pay particular attention to the signs of TIA. Survivors who experience a TIA after they have had a stroke should go to the emergency room immediately, because something in their treatment plan has not worked. Having a first stroke increases the likelihood of having another one, so take the warning seriously.
  • Anyone can experience a TIA, but the risk increases with age.
  • People at greater risks for stroke have higher risks for TIAs. Learn more about these risk factors including: smoking, cardiovascular diseases, diabetes, and blood clots called embolisms.
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Even though a TIA may seem to be resolved within minutes, with no noticeable or lasting effects, anyone who has symptoms should be rushed to the emergency room.

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When stroke symptoms are first noticed, it isn't safe to assume they will disappear without urgent medical care.

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We can all learn to spot a stroke and take action by calling 9-1-1. Educated bystanders can help patients get the care they need so these "warnings" are not overlooked.

Trained medical staff need to evaluate the patient's condition. Some signs are only visible with hospital equipment, so appropriate medical care is important, which may include:

Assessing vital signs and testing brain function for signs of immediate stroke. Initial assessment includes some quick tests to help determine if cranial nerves are intact, vision is normal, muscles have strength and speaking and thinking seem normal. Heart rate, temperature and blood may also help to provide an overall picture of what is happening.

Checking the blood flow and tissue within the brain tissue may be important to determine the cause of a TIA or any brief symptoms of stroke. These images can be seen using an magnetic resonance imaging (MRI) scan or a computerized tomography (CT) scan. An electrocardiogram (ECG) is often helpful. The main artery leading from the heart to the brain, called the carotid artery, may also be checked for signs of stiffening or blockage.

Assessing medical history and risks of cardiovascular disease, along with an evaluation of blood chemistry, can help determine the appropriateness of medication to prevent blood clots or a procedure to remove fatty deposits (plaques) from the arteries that supply blood to brain (carotid endarterectomy).

Referring a patient to a specialist is sometimes appropriate. When a TIA occurs in a young person and there are no clear risk factors for stroke, the patient may be sent to a neurologist for special testing to rule out vasculitis, carotid artery dissection and other types of injury or infection.

Anyone Can Have a Stroke. Everyone Should Be Ready.

Get rapid access to the most common stroke warning signs. Knowing the signs can help you spot a stroke F.A.S.T. and possibly save a life.

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Learn more about the different types of strokes. Ischemic | Hemorrhagic | Cryptogenic |

Understanding Stroke Risks

Learn about the stroke risk factors you can control, teat and improve. Share the high blood pressure and stroke infographic.

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