Every year, deep vein thrombosis (DVT) affects about one in every 1000 people in the UK, but it is important to know that venous thromboembolism (VTE) is largely a disease of hospitalised patients. Large studies have shown that the incidence of VTE in patients who are or who have recently been discharged from hospital are about 100 times greater than the incidence found in the community.
Anyone can develop a DVT, but there are a number of well-known factors that can increase the risk. Increasing age is a persistent and well-known risk factor for VTE, with patients over 60 years at higher risk. Another persistent risk factor is ‘thrombophilia’—the increased tendency to develop blood clots due to an abnormality in the clotting system of the body. Some risk factors are temporary, for example surgery. If an otherwise healthy person has surgery, the risk associated with the operation soon passes.
The more risk factors present, the greater the risk of developing a VTE. In this section, you can learn more about what these factors are and why they increase thrombosis risk.