Risk factors for venous thromboembolism (VTE)

Who is at risk from venous thromboembolism?

Every year, venous thromboembolism (VTE) affects about one in every 1200 people in Australia [1] and New Zealand[4]. 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 [2].

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 40 years at increasing risk [2]. Another persistent risk factor is called ‘thrombophilia’—the increased tendency to develop blood clots due to an abnormality in the body’s normal clotting system [2]. 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 [2]. Below, you can learn more about risk factors for VTE [3].

Always talk to your doctor if you have any concerns about risk factors or if you think you have symptoms of VTE.

High Risk
  • Hospital stay
  • Major surgery, such as abdominal/pelvic surgery
  • Knee or hip replacement
  • Major trauma: automobile accident or fall
  • Nursing home living
  • Leg paralysis
Moderate Risk
  • Older than age 65 years
  • Trips over 4 hours by plane, car, train, or bus
  • Active cancer/chemotherapy
  • Bone fracture or cast
  • Birth control pills, patch, or ring
  • Hormone replacement therapy
  • Pregnancy or recently gave birth
  • Prior blood clot or family history of clot
  • Heart failure
  • Bed rest over 3 days
  • Obesity
  • Genetic/hereditary or acquired blood clotting disorder


  1. Ho WK et al. The incidence of venous thromboembolism: a prospective, community based study in Perth, Western Australia. Med J Aust 2008; 189:144–7.
  2. Australian Commission on Safety and Quality in Health Care. Accessed 5 November 2018
  3. National Blood Clot Alliance. Blood clot risk and what we can do. Accessed 6 November 2018
  4. National Policy Framework:VTE Prevention in Adult Hospitalised Patients in NZ. Accessed 5 November 2018