Symptoms after thrombosis (post-thrombotic syndrome)

There is a lot of variation in how many symptoms PTS causes, and how severe they are. The symptoms usually affect only one leg, and are often similar to those of a blood clot.

The typical signs of PTS are:

• Fluid retention (edema) causing swelling in the ankles or lower legs
• Sensation of heaviness and pain in the leg, especially the lower leg
• Rashes and skin discoloration

The pain and swelling often get worse after standing or sitting for a long time. The swelling can make the skin on the lower leg feel tight. Other possible symptoms include tingling, itching, numbness, muscle cramps, and varicose veins.

Rashes and skin discoloration can develop over time: Inflammation and redness may occur. In some people, the skin dries out and flakes off; in others, it weeps and forms scabs. Sensitive, brownish-reddish patches of harder skin can sometimes later develop. Scars may also form that later become lighter colored. This discoloration isn't always as noticeable on darker skin. Injuries don't heal as well. Sometimes this leads to an ulcer or a chronic wound.

Post-thrombotic syndrome occurs when deep vein thrombosis has damaged the veins.

There are valves inside the veins called venous valves, which make sure that blood flows only toward the heart and not back down into the legs. Deep vein thrombosis can cause damage to these valves and the vessel walls, though. This means that blood builds up in the leg, increasing the pressure inside the veins. These veins expand and the venous valves can no longer close properly. In addition, the body releases immune cells and substances that attack the walls of the vein walls and the venous valves, which can make post-thrombotic syndrome even worse.

Because all of our veins are connected to each other, pressure also increases in nearby veins. Over time, fluid from the smallest vessels (the capillaries) can be pressed into the tissue, where it builds up. This affects the flow of oxygen-rich blood to that tissue. As a result, injuries heal more slowly, and open sores or ulcers may form. In addition, inflammation arises, which damages the veins even more and changes the surrounding tissue. This is how the typical skin symptoms develop.

The following circumstances increase the risk of post-thrombotic syndrome:

• after a blood clot near the back of the knee, the thigh, or, especially, the pelvis
• if blood clots keep on forming
• if the blood clot was not properly treated with anticoagulants

Additional risk factors include:

• Being very overweight
• Smoking
• Other venous disorders, such as varicose veins
• Older age

Deep vein thrombosis usually goes away on its own after about three to six months. Any symptoms you might have after that are most likely due to post-thrombotic syndrome.

It is not known exactly how many people develop PTS after having deep vein thrombosis. That happened in about 20 to 50 out of 100 people in studies.

It is not possible to predict exactly whether someone will get PTS or how it might develop over time. Bad cases with an open wound are relatively rare: About 5 out of 100 people who have PTS also develop an open sore on a lower leg.

Ulcers are a possible result of the high pressure in the veins. They may be caused by a minor injury, like bumping into the edge of the bed or cutting yourself while gardening. These venous leg ulcers usually form on the inner ankle or the shinbone and often weep. The damage then extends into the deeper layers of the skin.

The ulcer can lead to an open wound or become chronic. Open sores can also become infected if bacteria enter the wound.

It is not possible to tell apart the symptoms of thrombosis and post-thrombotic syndrome at first. But if typical PTS symptoms develop three to six months after you have DVT, a PTS diagnosis is very likely. Doctors can usually diagnose it based on its typical symptoms. More involved testing usually isn't needed to make a diagnosis.

Special ultrasound examinations (Doppler or duplex ultrasound) can make the blood vessels and the blood flow in the vessels visible. That helps doctors to see whether the venous valves have been damaged or if the blood clot has dissolved.

Ultrasound examinations of the blood vessels are mainly done by specialists for internal medicine and dermatology or by surgeons. They have special qualifications in angiology, phlebology, or vascular surgery.

In special cases, other imaging techniques such as MRI ( magnetic resonance imaging) can also make sense, like if doctors suspect pelvic vein thrombosis.

It is important to get proper treatment for deep vein thrombosis in order to prevent post-thrombotic syndrome. That usually involves taking anticoagulant medications (“blood thinners”) for three to six months. If you have other risk factors, such as cancer, doctors also recommend taking the medication for a longer period of time.

Anticoagulants help to treat the acute thrombosis and also lower the risk of developing thrombosis again. That risk is particularly high for the first few months after thrombosis.

Oral anticoagulants are the most commonly used medications. They are anti-clotting medications taken as tablets. But they can cause bleeding as a side effect, for example in the gastrointestinal tract. With some of these medications, you'll need to monitor the blood's clotting ability regularly and adjust the dosage accordingly. That is the case for vitamin K antagonists such as “Marcumar” and “Falithrom.”

Doctors sometimes recommend that people wear medical compression stockings for up to two years after DVT to prevent PTS. There is not much consensus about whether it helps. Studies have not led to any clear conclusions.

There are different ways to relieve the symptoms of PTS:

• Exercise: The calf muscles put pressure and tension on the veins when moving. This helps move blood away from the legs. Nordic walking, hiking, cycling and special calf muscle exercises are well suited.
• Avoid sitting or standing for long periods of time whenever you can: This causes blood to build up in the legs, which can make the symptoms worse – especially if you cross your legs when you sit. It is a good idea to walk around a little or to rock back and forth on the balls of your feet from to time if you have to stand for a long period. Moving your feet every now and then while sitting – for example, by moving them in circles – helps to improve blood flow. Elevate your feet up from time to time if possible to help the blood flow out of the veins.
• Skin care: Good skin care with moisturizing and lipid-replenishing products can soothe itching and feelings of tight skin. That can also keep your skin from drying out. It is best to talk to your pharmacist or doctor to find the best product for you.
• Reduce risk factors: Losing some weight if you are severely overweight, or quitting smoking can help, for example.
• Compression therapy: Compression therapy improves blood flow by putting pressure on the leg veins. This is done, for example, by wrapping the legs with compression bandages or wearing medical compression stockings. More rarely, compression machines are used which put pressure on the leg by inflating alternating cushions of air.

There are no reliable studies into how effective these treatments are, though. It is just not yet possible to say whether, when and how well they help with post-thrombotic syndrome.

Several herbal products are also offered to treat PTS. But doctors don't recommend them for treating post-thrombotic syndrome. That is because the effectiveness of these treatments has not been proven, and their side effects have not been studied enough.

Medical procedures might be an option to treat severe symptoms or certain complications:

• Sometimes a vein in the pelvis is severely constricted or blocked. This is referred to as Iliac vein compression syndrome (IVCS) or May-Thurner syndrome. A stent can then be placed via a catheter to improve blood flow.
• If varicose veins are making the symptoms of post-thrombotic syndrome worse, they can be removed or closed using sclerotherapy.

Leaking vein valves can also be operated on. But overall, surgery is only needed in rare cases to treat post-thrombotic syndrome. The advantages and disadvantages of different surgical techniques are not well studied, either.

Severe post-thrombotic syndrome with ulcers can be difficult to treat. Then it's a good idea to consult experts for internal medicine, dermatology, vascular medicine, and wound care. Specialist vascular clinics offer this kind of comprehensive care in Germany.

When people are ill or need medical advice, they usually go to see their family doctor or pediatrician first. Information about health care in Germany can help you to navigate the German healthcare system and find a suitable doctor. You can use this list of questions to prepare for your appointment.