Deep vein thrombosis (DVT) is a blood clot in a deep vein, usually in the legs. Things that lead to a blood clot in a vein include:
- Slowed blood flow, which can happen when you're not active for long periods of time.
- Abnormal clotting problems, which make the blood clot too easily or too quickly.
- Injury to the blood vessels, because blood is more likely to clot in veins shortly after they are injured.