A person can develop post-thrombotic syndrome after getting deep vein thrombosis. It can lead to mild symptoms or chronic pain and leg ulcers.

Deep vein thrombosis (DVT) is when a blood clot forms inside one or more of a person’s deep veins, usually in the leg. A complication that can develop from DVT is post-thrombotic syndrome (PTS). It affects 20–50% of people who have had DVT.

PTS can cause debilitating pain and affect a person’s quality of life.

This article outlines PTS, its causes, risk factors, symptoms, treatment, and more.

The legs of a person with post thrombotic syndrome-1.Share on Pinterest
The Good Brigade/Getty Images

PTS develops in the weeks and months following DVT. Blood clots in a vein can damage one or more of the valves that help blood travel in the right direction to the heart.

When the valves are damaged, they can block blood flow to the heart. Parts of the blood clot may also block blood flow. This causes fluid retention and pressure in the veins, which people may experience as swollen ankles and feet.

As blood flow worsens, people can develop leg ulcers, which can be painful. 5-10% of people who have experienced DVT get an ulcer.

Symptoms of PTS usually appear within 3–6 months of a person developing DVT but can appear up to 2 years later. Symptoms can include chronic pain and swelling of the leg.

The symptoms of PTS can range from mild to debilitating. However, options are available to help ease the symptoms and improve a person’s quality of life.

Certain factors may increase a person’s chances of developing PTS. These include:

  • being over 65
  • having obesity
  • getting DVT above the knee
  • having symptoms of a blood clot one month after doctors diagnose it
  • not taking blood thinner medication, such as warfarin, once doctors diagnose DVT
  • having more than one blood clot in the same vein more than once

Symptoms of PTS can range from mild to severe. They usually occur in the same location as the DVT. Symptoms can include:

If a person has symptoms of PTS, a doctor will ask them a series of questions before doing a physical examination.

There are no tests available for diagnosing PTS, but doctors use a scoring system called the Villalta score to diagnose and categorize the severity of PTS. If a person scores less than 5 points, they do not have PTS. If they score 15 or higher, they have severe PTS.

The initial pain and swelling that DVT causes can take time to get better. For this reason, doctors wait up to 6 months after the initial DVT diagnosis to diagnose PTS.

Doctors can treat PTS in various ways, including:

Compression therapy

Compression therapy is a common technique that helps increase blood flow and ease PTS symptoms. Compression therapy includes the use of:

  • Medical compression hosiery: This includes compression stockings. These apply more pressure than over-the-counter types. A person wears them throughout the day.
  • Compression bandages: These are similar to hosiery. They apply pressure to the affected area, and a person can wear them throughout the day. Long stretch bandages are stretchier than short stretch bandages.
  • Intermittent pneumatic compression (IPC) device: This fits over a person’s leg like a boot. It uses cuffs that fill with air and squeeze the leg.

Lifestyle recommendations

Doctors recommend lifestyle interventions to treat PTS. They include:

  • doing physical exercise to strengthen leg muscles and improve blood flow in the leg
  • achieving and maintaining a moderate weight, which may decrease pressure on the lower limbs and improve a person’s symptoms
  • using moisturizing creams as they prevent skin dryness, which can lead to ulcer development
  • elevating the leg while a person is resting
  • doing daily ankle exercises


Doctors may recommend a thrombectomy, a surgical procedure to remove the blood clot if it is causing severe PTS. There are two types of thrombectomy: a catheter aspiration thrombectomy, which involves using suction to remove the blood clot, and a mechanical thrombectomy, which involves breaking the blood clot into small parts to remove it.

Doctors may also consider catheter-directed thrombolysis when people have very large blood clots, relatively recent symptoms, and a low risk of bleeding.

Doctors reserve surgery for severe cases of PTS, as the procedures can be risky.

According to a 2021 study, there are limited treatment options available. The researchers suggest that future research should focus on the effectiveness of compression socks and exercise for managing PTS.

Medication and supplements

Currently no Food and Drug Administration (FDA)-approved medications or supplements are available to treat PTS.

A common complication of PTS is leg ulcers, also called sores. These can develop when the skin breaks, allowing bacteria to enter the underlying tissue and infect it.

A person may need pain medication, such as acetaminophen, to help with the pain while the ulcer is healing. If it becomes infected, a doctor may prescribe antibiotics. In severe cases, if an ulcer does not heal, doctors may need to surgically remove it, along with any damaged tissue.

To reduce the risk of developing PTS, a person must lower their risk of developing DVT. They should try:

  • staying active to encourage healthy blood flow around the body
  • avoiding sitting down for long periods, such as when traveling.
  • taking blood-thinning medication, also known as anticoagulants, if a doctor recommends it.
  • avoiding smoking, which affects the blood and how it clots
  • maintaining a moderate BMI

Learn about treatment, management, and prevention of blood clots here.

A person should contact their doctor if they experience any symptoms of DVT, such as pain, swelling, cramping and darkening of the skin of the affected leg.

They should also contact their doctor if they experience any symptoms of an ulcer on the affected leg. These symptoms include:

  • pain in the affected area
  • itching
  • swelling
  • discolored or hardened skin
  • a foul-smelling discharge coming from the sore
  • leg heaviness
  • tickling or prickling sensation, or paresthesia

PTS is a complication that can occur after a person has DVT. When a person has DVT, the blood clot can damage the valves in veins that allow blood to flow to the heart. Along with residual clots, this can prevent healthy blood flow and cause pressure to build up in a person’s veins.

A person can experience symptoms up to 2 years after having DVT. Symptoms include chronic pain, inflammation and darkening of the skin. DVT and PST mostly occur in the thighs or lower legs and can affect one or more veins.

Treatment for PTS includes lifestyle changes, such as maintaining a moderate weight and staying active. A person can do daily exercises to help strengthen leg muscles and wear compression devices to help reduce pain and inflammation.