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HealthInfo Canterbury

Deep vein thrombosis (DVT)

A deep vein thrombosis (DVT) is a blood clot in a vein that runs through the muscle of your calf or thigh. This clot can sometimes break off and travel to your lungs, causing a very serious condition called pulmonary embolism (PE).

DVT is treated with anticoagulant medication to stop more clots forming.


Because DVT can be serious, if you are experiencing any symptoms of a DVT, see your GP as soon as possible.

Symptoms of DVT include swelling and pain in the lower legSymptoms of DVT include:

You may have an increased risk of having a DVT for a number of reasons, including some medical conditions and long-distance travel.

See Reducing your risk of DVT or PE.

Your doctor will assess you and decide how likely it is that you have a DVT.

You may need a blood test called a D-Dimer. This detects blood clot pieces in your blood. This can be from a DVT but could also be from other conditions like a recent operation, injury, or pregnancy.

An ultrasound scan can check the blood flow in your veins to show the area where there is a clot.

Treating DVT

DVT is treated with anticoagulant (blood thinning) medicines which reduce the blood’s ability to clot. This stops the DVT getting bigger and from breaking loose.

Your doctor will choose the most suitable type of anticoagulant for you.

Types of anticoagulants:

You will need to keep taking anticoagulants for at least 3 months.

Your doctor may recommend you remain on anticoagulants for life to prevent another DVT. This is more likely if there was no cause found for your DVT or you have an ongoing risk of clots.

Some people have ongoing problems after a DVT such as pain, swelling and rash of the leg. This is known as post-thrombotic syndrome. Your doctor may recommend you wear compression stockings if this happens.

  HealthInfo recommends the following pages

On the next page: Reducing your risk of DVT or PE

Written by Haematology Department, Canterbury DHB (Risk factor information adapted from Health Navigator – Deep vein thrombosis) Adapted by HealthInfo clinical advisers. Last reviewed May 2020.

See also:

Blood-thinning medicines for DVT and PE

Page reference: 50819

Review key: HIDVT-21919