What Is Post-Thrombotic Syndrome?

Post-thrombotic syndrome is a possible complication of deep vein thrombosis (DVT). In DVT, a blood clot forms in one of the veins found deep in the body, usually in the legs or arms. This blood clot can stop blood flow and damage the veins.^1,2

What happens during post-thrombotic syndrome?

Post-thrombotic syndrome is a complication caused by one of these blood clots. Blood clots can damage the veins by physically blocking blood flow. The blockage can cause the veins to change shape and become wider or twisted.²

Blood clots can also send signals to the brain that increase inflammation. This inflammation might also play a role in developing post-thrombotic syndrome.²

Veins are responsible for sending blood back to the heart. But if the veins become damaged, some of the blood can start to flow backwards. This can cause the blood to pool and increase the blood pressure in the veins, leading to post-thrombotic syndrome.^1,2

Symptoms

Most people with post-thrombotic syndrome notice symptoms within two years after having a blood clot. Signs and symptoms of post-thrombotic syndrome may include:^1,2

• Leg pain
• Leg cramps
• Heavy feeling in the affected leg
• Itching or feeling of pins and needles in the legs
• Swollen veins
• Swelling in the legs
• Discoloration of the skin
• Sores on the legs

Symptoms may get worse at the end of the day or after you have been standing for a long time.¹

Risk factors

General factors that can put you at a higher risk for developing post-thrombotic syndrome include:^2,3

• Old age
• High body weight
• Varicose veins (dark, swollen veins found just below the skin)
• Previous damage to the veins

Factors related to DVT that can increase your risk include:^1-4

• Symptoms of DVT – DVT without symptoms is less likely to lead to post-thrombotic syndrome. On the other hand, people who have more symptoms of DVT are more likely to develop post-thrombotic syndrome.
• Location of DVT – Blood clots that form in the veins close to the hips and above the knees are more likely than other clots to lead to post-thrombotic syndrome.
• Recurrent DVT – Having DVT more than once can put you at a much higher risk for developing post-thrombotic syndrome.
• Residual vein thrombosis – If part of the blood clot remains in a vein after you have been treated for DVT, you are more likely to develop post-thrombotic syndrome.
• Poor DVT treatment – If DVT is not properly treated, it is more likely to lead to post-thrombotic syndrome.

Prevention

Preventing post-thrombotic syndrome includes reducing your risk for developing DVT. But if DVT occurs, getting treatment for DVT as soon as possible will help reduce the risk of future complications.^2,3

If you have already had DVT once, taking steps to reduce your risk of another DVT will also reduce your risk of developing post-thrombotic syndrome. The following lifestyle changes and treatments might help.^3,4

• Regular exercise – Experts highly recommend exercises that strengthen the heart and leg muscles.
• Leg compression – You can use compression stockings or other devices to apply pressure to your legs. They can help lower your risk of developing blood clots.
• Medicines – Anticoagulants are a group of drugs that can help prevent blood clots from forming. Statins are another type of drug that reduce swelling and damage caused by blood clots. Your doctor might prescribe an anticoagulant or statin after you have DVT to reduce your chances of developing post-thrombotic syndrome.

Treatment

Treatments for post-thrombotic syndrome mostly focus on managing the symptoms. Treatments include:^1-4

• Elevating your legs to help improve blood flow and reduce swelling. Try raising your legs through different exercises or placing pillows under your legs and feet when lying down.
• Wearing compression stockings to help relieve symptoms.
• Physical activity to help strengthen the leg muscles and improve blood flow.
• Moisturizers or steroid creams to treat ulcers or sores on the skin.
• Certain surgical procedures to restore blood flow within the affected veins. Surgery is usually recommended only in serious cases.