Topic Overview

What is a transient ischemic attack (TIA)?

Some people call a transient ischemic attack (TIA) a mini-stroke, because the symptoms are like those of a stroke but do not last long. A TIA happens when blood flow to part of the brain is blocked or reduced, often by a blood clot. After a short time, blood flows again and the symptoms go away. With a stroke, the blood flow stays blocked, and the brain has permanent damage.

A TIA is a warning: It means you are likely to have a stroke in the future. If you think you are having a TIA, call 911. Early treatment can help prevent a stroke. If you think you have had a TIA but your symptoms have gone away, you still need to call your doctor right away.

What are the symptoms?

Symptoms of a TIA are the same as symptoms of a stroke. They may include:

• Sudden numbness, tingling, weakness, or paralysis in your face, arm, or leg, especially on only one side of your body.
• Sudden vision changes.
• Sudden trouble speaking.
• Sudden confusion or trouble understanding simple statements.
• Sudden problems with walking or balance.
• A sudden, severe headache that is different from past headaches.

What causes a transient ischemic attack?

A blood clot is the most common cause of a TIA. Blood clots can be the result of hardening of the arteries (atherosclerosis), heart attack, or abnormal heart rhythms. Brain cells are affected within seconds of the blockage. That causes symptoms in the parts of the body controlled by those cells. Once the clot dissolves, blood flow returns, and the symptoms go away.

Sometimes a TIA is caused by a sharp drop in blood pressure that reduces blood flow to the brain. This is called a "low-flow" TIA. It is not as common as other types.

See a picture of a transient ischemic attack.

What tests do I need after a TIA?

Your doctor will do tests to look at your heart and blood vessels. You may need:

• Tests that show pictures of your brain and blood vessels, such as a CT scan, an MRI, a magnetic resonance angiogram (MRA), or an angiogram.
• A test that uses sound to check your blood flow (Doppler ultrasound).
• An echocardiogram (echo) to check your heart's shape and its blood flow.
• An electrocardiogram (EKG, ECG) to measure your heart rhythm.
• Blood tests, including a complete blood count and a fasting blood test to check for problems that could be causing your symptoms.