How is Deep Vein Thrombosis diagnosed?

The doctor will first ask about your symptoms, review your medical history and do a physical exam (check legs for swelling, tenderness or changes in colour).

Afterwards, if your doctor suspects that you have DVT, they may order one or more tests:

Duplex venous ultrasound: is the standard test for diagnosing DVT as it is non-invasive and widely available. It shows if blood is flowing normally or if there are blood clots in your veins.

D-dimer blood test: can help detect blood clots. Blood clots produce a protein called D-dimer. If the D-dimer test is negative, this can help rule out DVT.

X-ray of the vein (venogram): a dye is injected into large veins under a special X-ray to identify a blockage.

Magnetic resonance imaging (MRI) or Magnetic resonance venography (MRV): MRI shows pictures of organs and structures inside your body including blood vessels and veins. MRV shows images of the veins in specific locations in your body.

Chest CT scan: ordered if there is a risk that part of the blood clot has travelled to your lungs (pulmonary embolism)