Call 000 straight away for
- sudden shortness of breath or chest pain
- a racing or pounding heart, dizziness or fainting
- coughing up blood.
These can be signs that a clot has travelled to the lungs.
In short: before and after orthopaedic surgery, your team should assess both your risk of clots and your risk of bleeding, then agree a prevention plan with you. Plans usually combine getting up and moving early with stockings, compression devices or anti-clotting medicine. The risk continues after you go home, so follow your discharge plan, keep moving, and act quickly on a painful or swollen leg.
This page is general information. Your surgeon and hospital team decide which prevention is right for you, and their instructions come first.
What DVT and PE are
Venous thromboembolism (VTE) is the medical term for blood clots that form in the veins. It covers two linked problems:
- Deep vein thrombosis (DVT): a clot in a deep vein, usually in the leg or pelvis. It can cause pain, tenderness, swelling or redness of the leg, although some clots cause no symptoms.
- Pulmonary embolism (PE): part of a clot breaks off and blocks blood vessels in the lungs. It can cause shortness of breath, chest pain, coughing up blood, faintness or collapse, and it can be fatal.
Why surgery raises the risk
The Australian Commission on Safety and Quality in Health Care notes that clots are far more common in people in hospital than in the community, and that the risk continues after people go home. healthdirect lists surgery, broken bones and long periods without moving among the things that make clots more likely. Your own risk also depends on:
- your general health and how mobile you are
- a previous clot, or a family history of clots
- conditions such as cancer, heart failure or a previous stroke
- medicines that contain oestrogen, such as some contraceptive pills and hormone replacement therapy
- smoking and carrying extra weight.
Your risk is assessed, and so is your bleeding risk
Australia’s clinical care standard for VTE prevention expects every adult admitted to hospital to have their risk of clots formally assessed. Medicines that prevent clots can also increase bleeding, so your bleeding risk is assessed at the same time. Things that affect it include bleeding disorders, kidney or liver disease, recent bleeding, high blood pressure, stomach ulcers and other medicines.
Your clinicians weigh the two risks, discuss the options with you where there is a choice, and record the plan so that everyone caring for you can see it.
How clots are prevented
The Commission notes that prevention strategies reduce clots by about 70%. Your plan may include one or more of these:
Moving
Getting up early
Unless you are told otherwise, get out of bed as soon as you can after the operation. Lying or sitting still for long periods makes clots more likely. Even in bed, moving your feet and legs helps.
Mechanical
Compression stockings
Compression stockings are one of the mechanical methods used to prevent clots. If you are given stockings, wear them exactly as shown, and tell the staff if they are uncomfortable or leave marks.
Medicine
Anti-clotting medicine
Anticoagulant (anti-clotting) medicines can be used alone or with mechanical methods. You should be told how to take them, what the risks and benefits are, and whether any blood tests are needed.
Fluids
Staying hydrated
Being dehydrated can make clots more likely. Drink fluids unless you have been told to limit them.
Before you go home
The Commission’s consumer fact sheet says you should leave hospital with a written plan, developed with you, that includes:
- the clot prevention you received in hospital
- anything you need to continue at home, and how to use it
- whether you need blood tests or follow-up appointments
- the medicines to keep taking, and how to use them.
Your GP should receive a copy within two days.
What you can do
- Tell the team at your assessment if you have had a clot before, or if a blood relative has.
- Mention every medicine you take, including contraceptive pills, hormone therapy and medicines bought without a prescription.
- Get up and walk as soon as, and as often as, you are advised. Move your feet and ankles regularly when sitting or lying.
- Wear stockings and take anti-clotting medicine exactly as prescribed, for as long as prescribed.
- Avoid sitting still for long stretches, including on long car trips or flights; ask your surgeon before travelling.
- If you smoke, stopping helps your recovery in several ways, including your clot risk.
Warning signs
| Sign | What to do |
|---|---|
| Pain, swelling, tenderness or redness in the calf, thigh or ankle | See a doctor straight away: contact your surgeon’s rooms, the hospital or your GP the same day |
| Sudden shortness of breath, chest pain, a racing heart, dizziness or fainting, or coughing up blood | Call 000 |
| Bleeding or unusual bruising while taking anti-clotting medicine | Tell your doctor promptly; call 000 for heavy bleeding |
Questions to ask about clots
The Commission suggests asking:
- Am I at risk of blood clots, and why?
- What will be done in hospital to reduce the risk, and how does it affect my risk of bleeding?
- What can I do to help?
- If there are options, which would suit me?
- What do I need to keep doing after I leave hospital, and do I need to see my GP?
Common questions
How long will I need clot prevention after I go home?
It depends on your operation and your own risk, so there is no single answer. If you are to continue anything at home, such as an injection, tablets or stockings, your discharge plan should say what it is, how to use it and when to stop. Ask before you leave if it does not.
Can I stop my clot-prevention medicine if it causes bruising?
Do not stop it on your own. Tell your surgeon, GP or pharmacist about any bleeding or bruising that worries you, and seek urgent help for heavy bleeding.
I have had a clot before. Does that matter?
Yes. A previous clot, or a family history of clots, raises the risk. Tell the hospital team at your assessment so it is built into your plan.
Sources
- Australian Commission on Safety and Quality in Health Care. Venous Thromboembolism Prevention Clinical Care Standard. Accessed 2 Nov 2026.
- Australian Commission on Safety and Quality in Health Care. Venous Thromboembolism Prevention Clinical Care Standard: consumer fact sheet. October 2018.
- healthdirect Australia. Deep vein thrombosis (DVT). Last reviewed May 2025.
- Written by
- Altitude Creative, health content team, on behalf of Dr Walid Aly
- Clinical reviewer
- In progress
- Review date
- Clinical review in progress
- Next review due
- Set at clinical review
How this guide is written, reviewed and corrected: editorial policy.
In an emergency, call 000. This information is general and does not replace advice from your treating practitioner.