What is the cause of a transient ischaemic attack (TIA)?
In most cases, a TIA is caused by a tiny blood clot that becomes stuck in a small blood vessel (artery) in the brain. This blocks the blood flow, and a part of the brain is starved of oxygen. The affected part of the brain is without oxygen for just a few minutes, and soon recovers. This is because the blood clot either breaks up quickly, or nearby blood vessels are able to compensate. (There are other uncommon causes of a TIA. These include: blood clotting problems, tiny bleeds into the brain, blood disorders such as polycythaemia and sickle cell anemia where the blood is very thick, spasm of a small artery in the brain, and other uncommon problems of the brain or its blood vessels. These are not dealt with further in this leaflet.
