Last updated: Saturday, 05, February, 2011
Key InformationAppropriate Tests

See Thrombophilia


Most instances of arterial thromboembolism are due to abnormalities in the vessel wall and/or blood flow. Evidence does not support routine testing for the factors associated with venous thrombosis.



Aorta/proximal artery 

  • Atheromatous plaque
  • Thrombus

Local thrombosis

  • Atherosclerotic arterial disease
  • Aneurysm
  • Vasculitis
  • Local trauma

Predisposing abnormalities

Abnormal vascular surface

  • Atherosclerosis
See Atherosclerosis: risk assessment.
  • Prosthetic valve

Abnormal/turbulent blood flow 

  • Hypertension
  • Prosthetic valve
  • Arrhythmias

Blood abnormalities

  • Phospholipid antibody syndrome
APTT, lupus inhibitor; cardiolipin antibodies.


  • Heparin-induced thrombocytopenia


  • Homocysteinaemia
Homocysteine; testing for mutations of methyl tetra hydrofolate reductase (MTHFR) gene.


Predisposing abnormalities

Abnormal blood flow

Venous stasis 

  • Immobilisation
  • Cardiac failure
  • Varicose veins
  • Pregnancy

Vein wall injury/disease 

  • Pelvic, hip surgery
  • Pelvic carcinoma

Blood abnormalities:

Investigation may be indicated when venous thromboembolism is unexplained or recurrent; occurs in unusual sites; occurs in a young patient, or in a patient with a positive family history.

Acquired blood abnormalities

  • Phospholipid antibody syndrome

APTT, lupus inhibitor, cardiolipin antibodies.


  • Antithrombin deficiency
Antithrombin assay.
  • Pregnancy
See also Venous stasis, above.
  • Oestrogen theraphy
  • Protein C deficiency
    • Liver disease
    • Loading dose of oral anticoagulants
Patients with pre-existing protein C deficiency are at particular risk.
  • Heparin-induced thrombocytopenia
FBC, HITT's antibody screen and confirmatory testing.

Inheritedblood abnormalities

  • Factor V variant (V Leiden)
Activated protein C resistance test; molecular genetics - individual genetic disorders - Factor V Leiden mutation.
  • Antithrombin deficiency
Antithrombin assay.
  • Protein C deficiency
Protein C, protein S assays.
  • Protein S deficiency
Protein C, protein S assays.
  • Prothrombin gene mutation (G20210A)
Molecular genetics - individual genetic disorders - Prothrombin mutation.
  • Dysfibrinogenaemia
Thrombin time, reptilase time. For further investigation - consult pathologist.
  • Activated protein C resistance

Superficial thrombophlebitis




  • Lung
  • Pancreas
  • Gastrointestinal tract