Table 1

Risk factors for venous thromboembolism

*Where appropriate prophylaxis is used, relative risk is much lower.
†Inflammatory bowel disease, nephrotic syndrome, chronic dialysis, myeloproliferative disorders, paroxysmal nocturnal haemoglobinuria, Behçet’s disease.
Major risk factors (relative risk 5–20):
Surgery*
  • Major abdominal/pelvic surgery

  • Hip/knee replacement

  • Postoperative intensive care

Obstetrics
  • Late pregnancy

  • Caesarian section

  • Puerperium

Lower limb problems
  • Fracture

  • Varicose veins

Malignancy
  • Abdominal/pelvic

  • Advanced/metastatic

Reduced mobility
  • Hospitalisation

  • Institutional care

Miscellaneous
  • Previous proven VTE

Minor risk factors (relative risk 2–4):
Cardiovascular
  • Congenital heart disease

  • Congestive cardiac failure

  • Hypertension

  • Superficial venous thrombosis

  • Indwelling central vein catheter

Oestrogens
  • Oral contraceptive

  • Hormone replacement therapy

Miscellaneous
  • COPD

  • Neurological disability

  • Occult malignancy

  • Thrombotic disorders

  • Long distance sedentary travel

  • Obesity

  • Other†