HealthInfo West Coast-Te Tai Poutini
Deep vein thrombosis & 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 the normal flow of blood through your leg and can cause pain and swelling. Sometimes part of the DVT can break off and travel to your lung. This is called a pulmonary embolism (PE), which can be dangerous.
Being in a plaster cast slightly increases your risk of a DVT. This is 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:
|
|
Tell your doctor or nurse if you have any of these risk factors so they can decide if you need medication to reduce your risk of a clot.
Symptoms of a DVT with a cast
A DVT typically causes pain, a tender calf, swelling in the affected leg and sometimes redness.
If you have been injured and your leg is in a cast, some swelling is normal. But if you think the swelling is increasing despite keeping your leg raised, seek medical advice. Also seek medical advice if the pain is increasing even though you are taking what should be enough pain relief. You can contact the place that treated your fracture, your general practice team or the Emergency Department.
If your leg swells a lot after the plaster cast is taken off, it is also important to seek medical advice.
Reducing your risk of a DVT with a cast
- Stop smoking.
- Drink plenty of water.
- 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 health 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 place that treated you or see your general practice team.
Written by Orthopaedics Outpatients Department, Canterbury DHB. Adapted by HealthInfo clinical advisers. Last reviewed May 2025.
SourcesReview key: HILWI-174362
