Being aware of risk factors, and especially of your own risk factors is really important in helping you to avoid and protect yourself from thrombosis.

The the most common risk factors for thrombosis are:

  • Hospitalization for illness or surgery
  • Major surgery, particularly of the pelvis, abdomen, hip, knee
  • Severe trauma, such as a car accident
  • Injury to a vein that may have been caused by a broken bone or severe muscle injury
  • Hip or knee replacement surgery


  • Cancer and cancer treatments
  • Contraceptive pill for birth control in particular those that contain estrogen, such as the pill, patch or ring
  • Pregnancy, (including the six weeks after the baby is born)
  • Hormone therapy (HRT), which contains estrogen


  • A family history of blood clots
  • Obesity
  • Long-term bed rest
  • Long periods of inactivity including sitting for long period of time, especially with legs crossed

It is important that you discuss this with your doctor if any of these risk factors apply to you.

Risk Factors - Are You Aware

Download our Risk Factor and Symptom information leaflet