Deep Vein Thrombosis

What is a DVT?


A DVT or deep vein thrombosis is a blood clot which has formed on the inner wall of a leg vein.

Most blood clots are very small and the body is able to break them down itself. Some, however, grow larger and may significantly decrease or block the flow of blood. This will cause the leg to swell and become painful (phlebitis).

It is essential that you are fully aware of the symptoms and know when to seek advice. 

Print out the list of DVT symptoms (see below) and stick it on the fridge door. 

Stay safe

In some cases the clot becomes loose and travels via the heart to one or both lungs. This may interfere with the circulation of blood from the heart and thus reduce the amount of oxygen entering the circulatory system. This condition is referred to as a pulmonary embolism and calls for immediate, emergency treatment.


The cause of the condition is not understood.

Who Is At Risk?

There is a particular high incidence of deep vein thrombosis following any type of orthopaedic surgery but this risk is even higher for patients undergoing hip and knee replacements.

Anyone of any age can be affected but your risk increases if you: -

  • are over 40 years of age
  • in-bed
  • are immobilised e.g. after surgery or on a long haul flight.
  • have a history, or family history, of blood clots
  • are obese
  • have been treated for cancer
  • have any heart or circulatory problems
  • have thrombophilia (a condition which makes your blood clot more easily)
  • are pregnant or had a baby recently
  • are taking contraceptive pill (containing oestrogen) or hormone replacement therapy

How common is deep vein thrombosis?

It is estimated that about 3% of people having a hip replacement will develop one.


In many cases deep vein thrombosis will be asymptomatic (have no symptoms). Sometimes the leg will swell and become painful (phlebitis).

If a small clot travels to one or both lungs you may still not notice anything. However if a larger clot reaches the lung then you will probably experience shortness of breath, chest pains, sweating.

This is a medical emergency.  You must get help immediately.

So please print out the list of symptoms and put it somewhere easy to find like the fridge door!

If you experience any of the following symptoms in the days or weeks following surgery then CONTACT A HEALTH CARE PROFESSIONAL IMMEDIATELY.

  • Your leg is swollen or painful
  • Your leg feels numb or is tingling
  • The veins on your leg look bigger than normal or seem to stand out more
  • The skin on your leg is discoloured (red, purple or blue)other than any bruising around the operation site
  • You become short of breath
  • You cough up blood
  • You experience pain in your chest, ribs or back which gets worse if you breathe in deeply


If your doctor thinks you may have a DVT they will confirm the diagnosis by using a blood test (called the D-dimer blood test) or an ultrasound scan. It there is still any doubt you may undergo a contrast venography. Here a dye, which can be seen under X-ray, is injected into the leg vein. Any blockages to the circulation can then be spotted.


Medical treatment will be aimed at preventing new clots forming or existing ones growing larger. This is done principally by the use of anticoagulant medicines.

Medication can not dissolve any clots that you already have. Your body will deal with these over with time.

You may also be advised to wear compression stockings for up to two years after having a deep vein thrombosis.



Your surgeon is very aware of the risk and of all the preventative measures available. These may include: -

  • daily injections or medication to thin the blood and stop it clotting.
  • pressure stockings
  • foot or leg pumps - which keep the blood flowing by exerting pressure on the limb
  • movement - getting up and moving about keeps the blood moving


  1. Tell your doctor about any medication you are taking including anything you've bought over the counter of from a health shop. It is important that your doctor knows if you are taking anything that may thin your blood
  2. Take any preventative medication your doctor prescribes - regularly
  3. Keep moving - it's the best way to ensure that blood clots can't form - but it's not enough on it's own - take the medicine or injections
  4. Print out the DVT symptom check list and call for help immediately if any of the symptoms appear - don't wait - DVT can kill

Related Links: 

Preparing for Surgery 
The Day of Surgery 
Preparing for Recovery

Top of the Page

Back to Hip Replacement and Recovery