Do we know what causes a TIA?
There are many different causes of a TIA, and the causes are essentially the same as those for stroke and heart disease. High blood pressure is the most important cause of strokes and TIAs. Heart diseases are also a common cause of stroke, especially heart rhythm disturbances like atrial fibrillation or an irregular heart rhythm. What happens in that situation is that the heart is not beating regularly, so instead of the blood flowing quickly through the heart, it can form little eddy pools, like whirlpools, inside the chambers of the heart. Those eddy pools can lead to the formation of blood clots. Those little blood clots can travel through the blood vessels, and when they get into a small enough blood vessel in the brain, they block it and stop the blood flow, causing a stroke.
Another major cause is a narrowing in one of the arteries of the brain, particularly the carotid artery that comes up from the neck. This is the blood vessel that everybody can feel pulsing in their neck, carrying blood to the brain. A narrowing in a blood vessel is called a stenosis. With time and aging and certain risk factors, like high blood pressure and diabetes, the carotid and other vessels can narrow, and this leads to decreased blood flow to the brain. Sometimes it closes off completely and that can then lead to a stroke.
Who is most at risk for a TIA?
People who have high blood pressure, diabetes, high cholesterol, inflammation or who smoke and have a sedentary lifestyle are at risk. All of these conditions can gradually lead to damage to the heart or blood vessels over time.
There is also a misconception about strokes and TIAs that they only affect older people. We have seen an increase in strokes in younger people as well. We think part of the reason for that is a change in the occurrence of risk factors in younger people. There’s an obesity epidemic in the country, and there’s a lot of sedentary behavior. People aren’t getting enough activity and exercise. So, we’re seeing the occurrence of conditions like high blood pressure and diabetes in younger and younger people. Along with that come complications, which include strokes and TIAs.
Additionally, according to a 2020 study from the Centers for Disease Control and Prevention, one third of adults in the United States don’t know all five of the most common symptoms of a stroke, which are trouble speaking, problems with balance, vision problems, facial asymmetry and weakness or numbness in one’s arm or leg. So, at the public health and national level, education about risk factors and symptoms is extremely important.