Post-thrombotic Syndrome

Last updated June 29, 2024

Venous Stress Disorder
An In-Depth Guide for Patients and Health Care Providers


Normally, blood flows through veins out of the legs and arms back to the heart. Small valves in the veins enable the blood to flow in the right direction and prevent blood from flowing backwards and pooling in the veins of the legs and arms. A clot (thrombosis) in the deep veins of legs or arms (deep vein thrombosis, DVT) leads to an obstruction of blood outflow from the extremities back to the heart. Acute leg or arm swelling and pain, therefore result. This is called an acute DVT. When the body tries to heal from these clots the valves in the veins are often damaged. The obstruction of the veins and the destruction of valves lead to impaired blood flow.

If a vein is completely blocked, neighboring smaller veins may enlarge to bypass the obstruction. These bypassing veins are called collaterals and can get quite large, particularly in the pelvis and abdomen in patients who have thrombosis of the big veins in the abdomen (vena cava) or pelvis (iliac veins). Such collaterals can sometimes be seen as prominent veins underneath the skin. If good collaterals have formed, symptoms of leg swelling and pain may not occur or may only be mild. However, in some people collaterals do not get very large and can, therefore, not carry all the blood needed to drain the legs or arms; this then leads to chronic leg or arm swelling, pressure and pain.

Several different terms are used for the chronic symptoms that can occur after a deep vein thrombosis (Table 1). These terms all describe the same symptom complex. It is noteworthy that not all people who have these symptoms have had blood clots. Actually, the majority of people (88%) have not had documented blood clots. The same symptoms occur in people with dysfunction of the valves in the veins, heart failure, obesity and other, often not clearly identifiable causes. The best, most accurate, and most widely used medical term for this condition is “venous stasis syndrome.” If one refers to venous stasis syndrome occurring after a DVT, an appropriate term is “postthrombotic syndrome.” A good non-medical term is “venous stress disorder.” “Lymphedema” also refers to swelling of one or both legs or arms, but is usually not painful and does not lead to skin ulcers. However, its causes are different: it is due to obstruction of lymph vessels (and not the veins) that leads to a lack of drainage of fluid from the extremities, and, thus, to swelling.


Medical terms used:

  • Post-thrombotic syndrome (PTS)
  • Postphlebitic syndrome (PPS)
  • Venous stasis syndrome (VSS)
  • Chronic venous insufficiency (CVI)

Patient terms used:

  • Venous stress disorder
  • Chronic venous limb disorder


While some people who have had a DVT recover completely, others may be left with some symptoms in legs or arms: leg or arm swelling, pain, aching, heaviness, and cramping are some of the symptoms.

    • chronic extremity swelling
    • chronic (or waxing and waning) pain
    • unspecific discomfort of the extremity
    • diffuse aching
    • heaviness, tiredness and cramping of extremity
    • dark skin pigmentation (also known post-thrombotic pigmentation)
    • bluish discoloration of toes/fingers, foot/hand or diffusely of leg/arm
    • skin dryness
    • eczema
    • hardening of the skin
    • formation of varicose veins
    • skin ulcer (stasis ulcer)
    • “atrophie blanche” or “white atrophy (description in text)
    • “dermatoliposclerosis” (description in text)

An estimated 330,000 people in the United States have the post-thrombotic syndrome. Typically, the more extensive the DVT, the more severe the symptoms of post-thrombotic syndrome will be. However, this is not always so: even people who have had very extensive acute DVTs with severe symptoms may recover completely and may not be left with any long-term symptoms. Approximately 60% of patients will recover from a leg DVT without any residual symptoms, 40% will have some degree of post-thrombotic syndrome, and 4% will have severe symptoms. The symptoms of post-thrombotic syndrome usually occur within the first 6 months, but can occur up 2 years after the clot. If a patient has done well for 1⁄2 – 2 years after the clotting event it is highly unlikely that he/she will develop the post-thrombotic syndrome.

In people with arm DVT, post-thrombotic syndrome develops in approximately 15% of patients. People with DVT of larger veins, i.e. those in the shoulder and upper chest area (in medial terms “axillary or subclavian vein thrombosis”) and people who still have left-over clot after the acute event (residual thrombosis) appear to be at particular risk for post-thrombotic syndrome.

Little is known as to who will develop chronic symptoms and who will not. However, it is known, that people with DVT who wear daily compression stockings (see below) for several month after the acute DVT will develop significantly less post-thrombotic syndrome.


Prevention is the key issue. If a person has leg swelling after an acute DVT, the person should wear a compression stocking to decrease the swelling. The stocking should be custom fitted, i.e. a person’s leg should be measured to find a stocking that fits well. It needs to have a certain compression pressure, 35mm Hg (mercury) at the ankle, 25mm Hg at the mid-calf, and 18mm Hg just below the knee. This is also sometimes called a “grade 2” stocking. If the leg swelling is below the knee, then a below-knee stocking is appropriate, but if swelling also involves the thigh, then an above-knee stocking should probably be worn. However, research on the benefit of compression stockings and prevention of the post-thrombotic syndrome is ongoing. Sleeves (“gauntlets”) for post-thrombotic syndrome in the arm also exist and should be worn if there is arm swelling or pain.

Unfortunately, compression stockings are often not worn because they are deemed unsightly or are uncomfortable. People should know that stockings come in various skin-tone and fashion colors, different shapes, sizes and materials, and from a variety of companies. It is worthwhile to make inquiries to find the right stocking that fits well, is relatively comfortable, and is acceptable in appearance. If stockings tend to roll down, you may want to choose a stocking that has a rubber strip at the upper end or wear a garter belt or compression pantyhose. Stockings should be worn during the day, while standing; stockings do not need to be worn at night. They should be worn for weeks, months, or years to control symptoms. For example, if swelling has disappeared a few weeks or months after the acute DVT with the use of the stockings, you may stop wearing the stocking. If swelling recurs then the stocking should be worn again. If there is no more swelling, then stockings are not needed any more.

So-called “Anti Embolism Stockings” or “TED hose” are often given to people who are hospitalized and have had surgery. They put mild pressure on the legs to prevent blood from clotting and can, to some degree, prevent blood clots in the legs (DVT). However, due to their low compression pressures they are not useful to prevent or treat the post-thrombotic syndrome.

  • Elevation of extremity at rest and at night
  • Compression stockings, grade 2
  • Weight loss
  • Increased exercise with the strengthening of extremity muscles
  • Pain management
  • Compression pump
  • Vascular interventional radiology procedure: balloon opening and stenting of narrowed vein

Major compression stockings companies: 

  1. Jobst
  2. Juzo
  3. Medi USA
  4. Sigvaris
  5. Venosan

Major compression pump companies: 

  1. Bio Compression
  2. KCI
  3. Mego Afek

The National Blood Clot Alliance does not endorse specific medical products. Other products may also be available.

Elevation of the extremity above the level of the heart while resting or sleeping is also appropriate, if there is leg or arm swelling. Normalization of weight may also improve the symptoms. It is well possible that physical exercise and strengthening of the extremity muscles may improve the post–thrombotic syndrome. However, the role of physical exercise still needs to be investigated in clinical studies. In cases of pronounced swelling that does not improve with compression stockings, a compression pump should be tried (table 4). A battery-powered, transportable device is available (SCD EXPRESS by Tyco Healthcare), suitable for people who travel.

Pain management is important and needs to be individualized. Since many people with postthrombotic syndrome take anticoagulation medication, pain medications that increase the risk for bleeding when taken regularly should not be used. Drugs that contain aspirin or the so-called non-steroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen (Motrin®), naprosyn (Aleve®, Naproxen®, etc.) and others, should not be used. Drugs that can be considered are (a) the non-narcotic drugs, such as acetaminophen (Tylenol®), Celebrex®, tramadol (Ultram®), and others, or (b) the narcotic drugs, such as acetaminophen with codeine or oxycodon (Tylenol® #2, 3 or 4, Tylox®, Percocet®, etc.), hydromorphone (Dilaudid®, etc.), fentanyl patch (Duragesic®), and others. Pain management can be complex and input from a specialized Pain Clinic may be helpful. Neurontin® (Gabapentin) is a pain modifier that has been used for so-called neuropathic pain associated with diabetic neuropathy and other pain syndromes. It has not been studied in the pain of post-thrombotic syndrome, but could be tried for some time to see whether a person’s pain improves.

Balloon widening and stenting: Sometimes, people with post-thrombotic syndrome have a narrowing of one of the major veins in the pelvic area (iliac vein) or the abdomen (vena cava). This may be present from birth (called May-Thurner syndrome) or due to scarring of the blood vessel from a healed blood clot (stricture). If such a narrowing is present, it may be helpful to undergo a vascular radiology procedure during which the narrowing is ballooned open and stented (figure 2). This should only be undertaken in a center that is experienced in doing these procedures.

Venous skin ulcers may be difficult to heal. Visits with a vein or wound care specialist may be helpful to get expert care. Elastic bandages (Unna boots: bandages that contain a combination of calamine lotion, glycerin, zinc oxide, and gelatin), or foam dressings (Profore™; often lead to wound healing. However, this is a slow process. Diligent wound care is necessary.

Psychological and social aspects: The short and long-term impairment of physical functions may be frustrating, especially to people who were physically very active before their post-thrombotic syndrome. Oftentimes, such people will have to adjust their level of expectations, at least for the time being, and allow for their extremity function to slowly recover. However, the impairment of extremity function may also lead to permanent inability to work in the previous occupation and the need for retraining or for disability application. A visit with a social worker to discuss these issues may be helpful. It may also have a big impact on a person’s abilities to continue to pursuit his or her hobbies, such as athletic activities. And last but not least, it may negatively influence a person’s self esteem, family and interpersonal interactions.

SELECTED REFERENCES AND FURTHER RESOURCES: Kahn SR et al: Relationship between deep venous thrombosis and the post-thrombotic syndrome. Arch Intern Med. 2004 Jan 12;164(1):17-26. Elman EE at al: The post-thrombotic syndrome after upper extremity deep venous thrombosis in adults: A systematic review. Thromb Res. In Press, Corrected Proof, Available online 6 July 2005. Villalta S et al: Assessment of validity and reproducability of a clinical scale for the post-thrombotic syndrome (abstract). Haemostasis 1994; 24(Suppl1):158a. Ginsberg JS et al: Post-thrombotic syndrome after hip or knee arthroplasty: a cross-sectional study. Arch Intern Med 2000; 160:669-672. Heit JA et al: Trends in the incidence of venous stasis syndrome and venous ulcers: a 25 year population-based study. J Vasc Surg 2001;33:1022-1027. Goldhaber SZ et al: Pulmonary embolism and deep vein thrombosis. Circulation 2002;106:1436-1438.

Authors: Stephan Moll, MD, Department of Medicine, Division of Hematology-Oncology, University of North Carolina School of Medicine, Chapel Hill, NC. Susan R. Kahn, MD, Centre for Clinical Epidemiology and Community Studies, Jewish General Hospital, Montreal, Canada Acknowledgement: Review of manuscript: Elizabeth Varga, Columbus, OH; Graphic Design: Jeff Harrison, Wilmington, NC.

Participate in a Clinical Trial


NIH-sponsored study – the Chronic Venous Thrombosis: Relief with Adjunctive Catheter-Directed Therapy study, or C-TRACT study – is designed to evaluate whether endovascular therapy procedures improve quality of life for people with long-term complications of deep vein thrombosis (DVT).

Learn more about this study 

Current News

Antithrombin Deficiency

Antithrombin Deficiency An In-Depth Guide for Patients and Healthcare Providers By Stephan Moll, MD Last reviewed on July 22, 2024…

Introducing the NBCA Advocacy Institute

To put an end to the 100,000 deaths each year to blood clots, the National Blood Clot Alliance is accelerating…