Deep vein thrombosis and plaster casts Tepe ia-auraki hōhonu me ngā tākai ukutea

A deep vein thrombosis (DVT) is a blood clot that forms in a vein deep in your leg. The clot blocks normal blood flow through your leg and can cause pain and swelling. Having your leg in a plaster cast slightly increases your risk of a DVT.

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Causes of DVT with a leg cast

Your leg plaster cast means you have a slightly higher DVT risk because you are not moving around as much as usual, so you have reduced blood flow.

Surgery and broken bones can also add to this risk because they can cause changes in your blood vessels.

Other things that can increase your risk of DVT include:

  • a previous DVT or a blockage in one of the blood vessels in your lungs (pulmonary embolism)
  • a family history of DVT or pulmonary embolism
  • a blood clotting disorder
  • recent surgery or bed rest
  • recent long-distance travel (more than 4 hours) by plane, car or train
  • cancer
  • pregnancy
  • smoking
  • being an unhealthy weight.

Tell your healthcare provider if you have any of these risk factors so they can decide if you need medication to reduce your risk of a clot.

Deep vein thrombosis (DVT)

Pulmonary embolism

Blood clotting disorders

Symptoms of a DVT with a leg cast

A DVT typically causes:

  • pain or tenderness in your calf
  • swelling in the affected leg
  • redness (sometimes).

When to get urgent medical advice

If you have been injured and your leg is in a cast, some swelling is normal. But you should seek urgent medical advice if:

  • you think the swelling is increasing despite keeping your leg raised
  • the pain is increasing even though you are taking pain relief
  • your leg swells a lot after the plaster cast is taken off.

Contact the healthcare provider that treated your injury, your usual healthcare provider or go to the emergency department.

You can also call Healthline on 0800 611 116 for free health advice 24 hours, 7 days.

Complications of a DVT

Sometimes part of the DVT (clot) in your leg vein can break off and travel to your lung. This is called a pulmonary embolism (PE), which can be dangerous.

Pulmonary embolism

Reducing your risk of a DVT with a leg cast

  • If you smoke, stop smoking.
  • Drink plenty of fluids.
  • Do regular exercises, such as moving your toes or walking around with the help of crutches. Be careful not to put weight on your injured leg if you have been told not to.

Your healthcare provider will let you know if you are at a high risk of developing a DVT and need medication to help prevent it.

If you have any concerns about your injury or your plaster cast, phone the clinic that treated your injury or see your healthcare provider.