Anticoagulation UK

Post-thrombotic syndrome

Post thrombotic syndrome is a complication of deep vein thrombosis affecting around 20-40% of people with a history of DVT.

If you have had a deep vein thrombosis (DVT), usually in the leg, the blood clot in the vein of your calf can divert the flow of blood to other veins, causing an increase in pressure on the vein walls which can damage the valves that work to keep the blood circulating in the leg.

PTS may develop within six months and up to two years after an initial DVT.  People who have a recurrence of DVT will be at heightened risk of the condition.


Symptoms can be mild to moderate to severe and can differ between individuals. Some people find that standing or sitting for long periods can cause discomfort in the affected limb and this can impact on the patient’s general wellbeing and day-to-day activities

Symptoms include:

  •  Chronic pain (in the calf)
  • Sensation of heaviness
  • Swelling
  • Cramp, itching and tingling
  • Hardening of the skin
  • A rash
  • Discolouration of the affected leg
  • Ulcers on the calf in severe cases

If a DVT develops in your thigh vein, there's an increased risk of post-thrombotic syndrome occurring. It's also more likely to occur if you're overweight or if you've had more than one DVT in the same leg.

Managing PTS

You may be advised to manage your symptoms as follows:

  • Elevating the leg to reduce swelling and discomfort
  • Wearing elastic compression stockings (ECS) can alleviate the symptoms once developed, however, recent research has shown that ECS did not prevent PTS after a DVT
  • Intermittent Pneumatic compression devices (IPC) consist of an inflatable garment (sleeve or boot for the leg and an electrical pneumatic pump that fills the garment with compressed air. The garment is intermittently inflated and deflated with cycle times and pressures that vary between devices
  • Weight loss – to reduce pressure on limbs
  • Regular exercise to increase circulation

PTS can be debilitating, causing health anxiety and fear around recurrence of blood clots. Recent published research has shown that some people can develop psychological issues that may continue for months and years.

Patients should discuss any concerns with their doctor and may benefit from counselling, cognitive behaviour therapy (CBT), a talking therapy that can help you manage your problems by changing the way you think and behave. Group therapy and patient forums can also help people share information about ways in which they can manage the condition positively.

Preventing PTS

As PTS is a complication of blood clots, reducing the risk of blood clots where possible is very important as a way of preventing PTS from occurring.

Risk factors for blood clots can include:

  • Being admitted to hospital for surgery or for a medical illness
  • Previous blood clots
  • Family history of blood clots
  • Cancer and treatment
  • Pregnancy
  • Oral contraceptive pill and hormone replacement therapy (HRT)
  • Clotting disorders (thrombophilia), also known as sticky blood
  • Long distance travel and long periods of limited mobility with a sedentary lifestyle

If you are going into hospital for a surgical procedure or medical reason, you should be assessed as to your risk of blood clots. If you are found to be at an increased risk, you should be offered anticoagulant therapy. The treatment may continue for a short period after you are discharged.