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Deep vein thrombosis (DVT)

Tepe ia-auraki hōhonu

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

DVT is treated with blood thinning medication (anticoagulants) to stop more clots forming.

Symptoms of a DVT


A DVT can be serious. If you have any symptoms of a DVT, see your general practice team as soon as possible.

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

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

See Reducing your risk of DVT or PE for information about the risk factors and how to reduce your risk.

Diagnosing a DVT

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

You may need a blood test called D-Dimer. This detects blood clot pieces in your blood. If the test finds blood clot pieces in your blood, they could be from a DVT, but they 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 a DVT

A DVT is treated with blood thinning (anticoagulant) medicines that reduce your 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'll need to keep taking anticoagulants for at least three months.

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

After a DVT, some people have ongoing problems with their leg such as pain, swelling and a rash. 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: Pulmonary embolism (PE)

Written by HealthInfo clinical advisers. Last reviewed February 2023.


See also:

Blood-thinning medicines for DVT and PE

Page reference: 50819

Review key: HIDVT-21919