A TIA results from a temporary blockage of the blood supply to the brain. The carotid artery in the front of the neck is a major supply of blood to the brain. A build-up of plaque and hardening of this artery can slow or stop blood flow.
Reasons for the blockage may include:
- A blood clot or a piece of plaque (called an embolus) from inside the wall of an artery breaks off and blocks blood flow to a portion of the brain.
- A blood clot dislodges from the heart and moves to the brain.
- Temporary low blood pressure in the brain may occur due to narrowed arteries in the neck.
Blood and blood-clotting disorders such as:
- Anemia (too few red blood cells)
- Polycythemia (too many red blood cells)
- Hyperviscosity (abnormal thickening of the blood)
- Vasculitis or blood vessel inflammation
- Endocarditis (infection of the lining of the heart)
Factors that increase your chance for TIA and stroke are similar:
- Family history of stroke
- Age: 45 or older (highest risk 60-80 years of age); more common in men than women in younger age groups
- Atrial fibrillation —a common irregular heart rhythm
- High blood pressure
- Excessive alcohol use
- High cholesterol
- Certain medical conditions: