Blood clots

Key facts Blood clotting can become a problem when it stops your blood from flowing properly. A blood clot that forms in a blood vessel is called a thrombus. Blood clots can cause different problems depending on where they are in your body. What are blood clots? Your blood is able to clot so that you don’t lose too much blood if you are injured. But blood clotting can become a problem when it stops blood flow through blood vessels. Blood clots in blood vessels can be fatal if they aren’t treated. They can lead to problems such as a stroke, heart