What is post-thrombotic syndrome?

Post-thrombotic syndrome is a condition that can happen to people who have had a deep vein thrombosis (DVT) of the leg. The condition can cause chronic pain, swelling, and other symptoms in your leg. It may occur in the weeks or months after a DVT.

Veins are the blood vessels that bring oxygen-poor blood and waste products back to the heart. Arteries are the blood vessels that bring oxygen-rich blood and nutrients to the body. A DVT is a blood clot that forms in a vein deep inside the body. In most cases, this clot forms inside 1 of the deep veins of the thigh or lower leg.

The veins in your legs have tiny valves that help keep blood moving back up toward the heart. But a DVT may damage 1 or more of these valves. This causes them to weaken or become leaky. When this happens, blood starts to collect in your legs.

DVT is a common condition, especially in people over age 65. Post-thrombotic syndrome affects a large number of people who have had DVT. It can happen in anyone of any age.

What causes post-thrombotic syndrome?

A variety of conditions can increase your chance of getting a DVT, such as:

• Recent surgery, which decreases your mobility and increases inflammation in the body, which can lead to clotting

• Health conditions that limit your mobility, such as an injury or stroke

• Long periods of travel, which limit your mobility

• Injury to a deep vein

• Inherited blood disorders that increase clotting

• Pregnancy

• Cancer treatment

Who is at risk for post-thrombotic syndrome?

Certain factors may increase your risk for post-thrombotic syndrome, such as:

• Being very overweight

• Having a DVT that causes symptoms

• Getting a thrombosis above the knee instead of below it

• Having more than 1 DVT

• Having increased pressure in the veins in your legs

• Not taking blood thinners after your DVT

What are the symptoms of post-thrombotic syndrome?

In some cases, post-thrombotic syndrome causes only a few mild symptoms. In other cases, it can cause severe symptoms. The symptoms occur in the same leg that had the DVT, and can include:

• A feeling of heaviness in the leg

• Itching, tingling, or cramping in your leg

• Leg pain that’s worse with standing, and better after resting or raising your leg

• Widening of leg veins

• Swelling in your leg

• Darkening or redness of the skin around your leg

How is post-thrombotic syndrome diagnosed?

Your healthcare provider will ask about your health history, including if you have had a DVT. They will ask about your symptoms and give you a physical exam. This will include a careful exam of your leg. You may also need some tests, such as:

• Ultrasound. This is done to look for problems with the leg vein valves.

• Blood test. This is done to check for clotting problems with your blood.

Healthcare providers often use something called a Villalta score to assess post-thrombotic syndrome. This scale rates the severity of your symptoms and signs. A score higher than 15 means that you have severe post-thrombotic syndrome.

How is post-thrombotic syndrome treated?

Compression therapy is the main treatment for post-thrombotic syndrome. This helps to increase the blood flow in your veins, and decrease your symptoms.

You may be given prescription-grade elastic compression stockings. These apply more pressure than the type you can buy over the counter. These are worn during the day, on the leg that had the DVT. You also may also be given an intermittent pneumatic compression (IPC) device. This device applies pressure on the veins of your leg.

Correct skin care is also key. Your healthcare provider may advise that you use a product to lubricate your skin, such as petroleum jelly. Barrier creams that contain zinc oxide can also be helpful. In some cases, you may need a steroid cream or ointment to treat your skin. If you have leg sores (ulcers), they may need special treatment.

In some cases, your provider may advise surgery. This can be done to remove a blockage in a major vein. It can also be done to repair the valves in your leg veins.

Living with post-thrombotic syndrome

Symptoms often improve with treatment, but your symptoms may not all go away. It may help if you:

• Ask your provider about exercise training

• Walk every day to increase calf muscle strength and general health

• Do daily ankle flexing exercises to strengthen calf muscles

• Raise (elevate) your legs a few times a day and when you are at rest

• Pay careful attention to dry, itching skin and any skin changes. Ask your provider what types of skin moisturizers to use. 

What are possible complications of post-thrombotic syndrome?

Post-thrombotic syndrome can cause leg sores (ulcers). If so, you will need to have wound care. Aspirin and a medicine called pentoxifylline may help aid ulcer healing. If an ulcer becomes infected, you may need antibiotics. Severe ulcers that don’t get better with medicines and wound care therapy may need surgery to remove the damaged tissue.

What can I do to prevent post-thrombotic syndrome?

You can reduce your risk of post-thrombotic syndrome by lowering your risk of DVT. Not moving or walking for long periods of time raises your risk of DVT. If you are immobile due to a health condition or surgery, your healthcare provider will advise you how to prevent DVT. This may include:

• Taking blood-thinning medicine, such as warfarin

• Using prescription-grade compression stockings

• Using a compression device

• Moving and walking as soon as you are able

Treating DVT right away is the best way to prevent post-thrombotic syndrome. Take blood-thinner medicine exactly as prescribed. Don’t miss any follow-up tests to check your blood levels of the medicine. Use your compression devices exactly as prescribed.

When should I call my healthcare provider?

Call your healthcare provider right away or get medical care right away if you have:

• A sore or a warm, painful area on your leg

• Symptoms of an infected sore on your leg (heat, redness, warmth, fluid leakage, odor, or a fever)

• Symptoms of DVT, such as leg swelling, pain, or warmth

Key points about post-thrombotic syndrome

• Post-thrombotic syndrome is a condition that can happen to people who have had a deep vein thrombosis (DVT) of the leg.

• It can cause chronic pain, swelling, and other symptoms in your leg. It may occur in the weeks or months following a DVT.

• Certain medical conditions increase your chance of getting a DVT.

• Compression therapy is the main treatment for post-thrombotic syndrome. You might also need medicines, topical creams, or surgery.

• Post-thrombotic syndrome may cause skin sores (ulcers) that need special therapy.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are and when they should be reported.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.