This kind of blood clot in the leg can lead to a fatal pulmonary embolism. Anticoagulant medications and compression stockings can help prevent acute thrombosis and prevent complications.

As a blood clot in the leg that’s only been present for 14 days or less, acute thrombosis can be difficult to diagnose as it doesn’t always cause symptoms. When it does, symptoms can include leg pain, redness, and swelling.

However, it’s common for the first sign of acute thrombosis to be a pulmonary embolism, a complication of acute thrombosis that occurs when a piece of clot breaks away and travels to the lungs. In severe cases, pulmonary embolisms can be fatal. Acute thrombosis can be treated with medication.

Treatment reduces the risk of pulmonary embolism and other complications and typically involves anticoagulant medication and compression stockings.

A thrombosis is a blood clot. An acute thrombosis is a serious condition that causes a clot to form in a leg vein. Acute thrombosis in the leg can be very serious. It can lead to permanent leg damage or to a potentially fatal complication called a pulmonary embolism that occurs when a piece of the blood clot breaks off and enters the lungs.

An acute thrombosis refers to a thrombosis in the legs that has been present for less than two full weeks. The primary symptoms of acute thrombosis are leg swelling and pain.

When thrombosis lasts for longer than 28 days, it’s called chronic deep vein thrombosis (DVT). Chronic DVT can stick to artery walls or completely block blood flow. Acute thrombosis is typically easier to treat and is less likely to lead to permanent leg damage.

For many people with acute thrombosis or chronic DVT, the first sign of the condition is a pulmonary embolism. It’s common for thrombosis to not cause symptoms for weeks or months until an embolism occurs.

However, symptoms such as leg swelling, pain, and redness do develop in some people with acute thrombosis.

If you experience a blood clot or any of these symptoms, it’s important to make a medical appointment as soon as possible. At your appointment, you and your doctor will discuss your symptoms and your medical history.

If they suspect you have acute thrombosis, they’ll order tests, such as:

  • Blood tests: A blood test called a D-Dimer test that can look for clot pieces in your blood can help diagnose acute thrombosis.
  • Ultrasound: An ultrasound can help doctors see how fast blood is flowing throughout your body. This can help them spot any blockages that clots could cause.
  • Venogram: A venogram is a test that uses a specialized dye along with an X-ray to look for clots. The dye will be injected into a vein in your foot. The dye will identify the location, and the X-ray will create images as it travels up your leg.

Anyone can develop a blood clot at any time. However, there are some risk factors that make developing an acute thrombosis more likely. These include:

Without treatment, acute thrombosis can lead to pulmonary embolism. Sometimes pulmonary embolisms are mild and cause no symptoms, but severe pulmonary embolisms can block blood vessels in your lungs and can be fatal. About 1 out of every 10 people with thrombosis that goes untreated develops a severe pulmonary embolism, according to Scotland’s NHS inform.

Acute thrombosis is treated with medications called anticoagulants. These medications are blood thinners. They stop your body from making as many blood clots and prevent the blood clots you already have from growing. Commonly, you’ll be given an injection of the anticoagulant heparin right away to prevent clots from forming.

You might then continue treatment by taking a different anticoagulant, such as warfarin, to help ensure new clots don’t form. Warfarin is a tablet medication that you’ll take daily for as long as your doctor recommends.

This might be for several months, or long term, depending on what your doctor thinks is best for you. Warfarin isn’t the right option for everyone with acute thrombosis. Your doctor might prescribe other, newer anticoagulants if you’re unable to take warfarin.

In addition to medication, your doctor might recommend that you wear compression stockings. Compression stockings help prevent pain, swelling, and ulcers. They also help prevent the risk of permanent leg damage and future thrombosis.

You’ll likely also see a physical therapist who will help you develop an exercise routine. Physical activity helps reduce pain and is an important part of preventing another thrombosis.

Additionally, your doctor and physical therapist might advise you to keep your legs elevated when you sit or rest. This can also help prevent pain and swelling.

Acute thrombosis is a blood clot that has been present for less than 14 days. It’s a serious condition that can lead to permanent leg damage and a fatal pulmonary embolism if left untreated. Not everyone with acute thrombosis experiences symptoms. Sometimes a pulmonary embolism is the first sign of an acute thrombosis. When symptoms do occur, they can include leg pain, swelling, and redness.

The primary treatment for acute thrombosis is anticoagulant medications. Increased daily activity and leg elevation while at rest are typically also recommended. Once treatment is completed, compression socks may be used to help prevent further blood clots and complications, such as chronic leg swelling.