Deep vein thrombosis (DVT)

Thrombosis typically develops in one side of your body, so the symptoms usually affect only one leg.

The common signs of deep vein thrombosis include:

• Pain in a leg or hip covering a larger area
• Tenderness
• Swelling and a tight feeling
• Warm, reddish skin. The darker the skin, the harder it is to see. On darker skin, it looks more bluish-purple.
• Muscle cramps

The symptoms depend on where the clot is blocking the vein: near the calf, behind the knee, or in the thigh or pelvis. Thrombosis below the knee usually only causes symptoms in the lower leg. Thrombosis that is higher up or more extensive can also lead to symptoms in the thigh or pelvis.

Blood clots may form if the blood flow in a vein is too slow, if the blood clots too easily, or if the wall of a blood vessel is damaged. That may result from:

• Longer periods of bed rest, for instance in the hospital, after a bone fracture or injury: Spending a lot of time in bed and not moving much can lead to a build-up of blood in a leg.
• Blood clotting disorders, such as those caused by congenital conditions like antiphospholipid syndrome (APS)
• Major surgery or serious injuries that damage the blood vessels. The body then increases your blood's clotting ability to stop the bleeding and close wounds.

Various other things can increase someone’s risk of developing thrombosis: Here are some examples:

• Having thrombosis before
• Being over the age of 60
• Family history (meaning that your parents or siblings have had thrombosis)
• Cancer and treatment for cancer
• Heart disease like heart failure, a heart attack or atrial fibrillation
• A recent stroke
• Being severely overweight (obese)
• Contraception using hormonal contraceptives that contain the hormones estrogen and progestin (such as the combined contraceptive pill)
• Hormone therapy during menopause
• Very noticeable varicose veins
• Smoking
• Some inflammatory conditions, such as inflammatory bowel disease or pneumonia
• Pregnancy
• Regular long-haul journeys where you spend a lot of time sitting

The likelihood of developing a blood clot increases if you have multiple risk factors.

One common complication of DVT is known as post-thrombotic syndrome (PTS). There are no exact figures available on how many people have PTS in Germany. In studies, approximately 20 to 50 out of every 100 people developed post-thrombotic syndrome following a deep vein thrombosis. PTS is caused by if the DVT has damaged the walls or valves of a vein, causing the blood to constantly build up in the vein. If you still have the symptoms of deep vein thrombosis 3 to 6 months later, it is likely to be PTS.

People with PTS may have a swollen leg that feels heavy and hurts. The skin on their leg may also become discolored and itch, and a rash may develop. Severe PTS can cause even a minor injury to develop into a chronic wound. It is important to seek medical advice quickly if you have these symptoms.

A rarer but more serious complication of deep vein thrombosis is known as pulmonary embolism. This happens if the blood clot breaks away from its original site and is carried through the blood stream to the lungs, where it blocks a blood vessel. Signs of a pulmonary embolism include:

• Sudden shortness of breath
• Chest pain (especially when breathing in or coughing)
• Feeling dizzy or faint, or losing consciousness
• Rapid heartbeat
• Bloody phlegm when coughing

If pulmonary embolism develops, then it usually does so within two weeks of the DVT developing. A pulmonary embolism must be treated quickly because it can lead to life-threatening heart failure.

Deep vein thrombosis can’t be diagnosed for sure based on typical symptoms alone. Symptoms such as pain, swelling, and skin redness can also have other causes, like phlebitis, varicose veins, erysipelas, or peripheral arterial disease (PAD).

Your doctor will see how likely it is that you have deep vein thrombosis after talking with you in detail about your medical history and giving you a physical examination. The next steps depend on this result.

A blood test (D-dimer test) is often used. This test is done to detect D-dimers in your blood. The body produces these products when it breaks down a blood clot. If the results of the test are normal, doctors can be quite sure that you don’t have DVT. If the results are abnormal, a special kind of ultrasound scan (Doppler ultrasound) is done in order to confirm the diagnosis. An ultrasound exam allows the doctor to see the condition of your veins and how your blood is flowing through them.

If it’s very likely that you have deep vein thrombosis, the doctor will typically perform an ultrasound exam right away.

Other imaging procedures, such as an X-ray scan using a catheter (phlebography), magnetic resonance imaging (MRI), or computed tomography (CT) of the veins, are rarely necessary. A contrast medium (dye-like substance) is injected in these procedures to make the blood vessels visible.

There are different ways to try to prevent DVT. People who are recovering from surgery or an injury usually need to spend a few days resting in bed. But it's still important to move if you can and to get up again as soon as possible. Doctors recommend doing small exercises to help with the circulation of your blood, like wiggling your foot.

Anticoagulants can be used for a few days or weeks to help reduce blood clotting. Their suitability will depend on things like whether you have had surgery, how major it was and whether you have other risk factors for thrombosis. These medications can be injected or swallowed.

You can also wear medical compression stockings. The stockings put pressure on your veins, which helps the blood to flow. If you're already using anticoagulants, you usually won't need to wear compression stockings. But they are an option for people who can't use anticoagulants. That is rare, though. Compression devices are increasingly being used for people who have to stay in bed. They apply alternating pressure to the leg by inflating a cuff.

Deep vein thrombosis is usually treated for a few days in the hospital or in an outpatient setting.

To make sure that the blood clot dissolves completely, doctors recommend taking anticoagulant (anti-clotting) tablets for three to six months after having the acute treatment. Sometimes it’s a good idea to take them for even longer too. It is important to take the medicine as prescribed. That helps to prevent both another thrombosis and post-thrombotic syndrome. Anticoagulants can cause bleeding as a side effect, though.

To lower the risk of post-thrombotic syndrome, doctors sometimes recommend wearing compression stockings for up to two years. Studies on their effectiveness haven't shown any clear results, though. So it’s best to talk with your doctor about whether compression stockings are a good idea for you.

Some people aren't able to use anticoagulants – for example, because they tend to bleed more. In that case, non-drug treatments such as compression stockings or compression devices are given greater consideration.

When people are ill or need medical advice, they usually go to see their family doctor or pediatrician first. Vascular specialists called phlebologists are particularly helpful. These may be certified doctors for internal medicine specializing in vascular medicine (angiology), dermatology or surgery.

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.