Deep vein thrombosis (DVT) is a potentially life threatening blood clot that can occur in the lower legs, pelvis, thighs, or even the arms. It can cause throbbing pain, swelling, or redness.

DVT is a type of venous thromboembolism (VTE), which is when a blood clot forms in a vein.

The Centers for Disease Control and Prevention (CDC) explain that DVT does not always cause symptoms. Some people may be at higher risk of DVT.

This article explores DVT in more detail and discusses its symptoms, potential complications, and risk factors. It also explores diagnostic tests, treatment options, and preventive measures for DVT.

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Possible symptoms of DVT include:

  • throbbing pain that usually affects one leg
  • swelling in one leg
  • skin that feels warm
  • redness
  • swollen veins that feel sore when touched

These are three possible complications that may arise in people with DVT:

Pulmonary embolism

DVT may lead to pulmonary embolism. This is when parts of the blood clot break off, travel through the bloodstream, and end up in the lungs.

People who have developed pulmonary embolism may not always have symptoms. Sometimes, symptoms appear suddenly or come on slowly over time.

They may include:

  • shortness of breath
  • heavy breathing
  • an increase in heart rate
  • pain with deep breathing

Some people may cough up blood and develop lightheadedness and anxiety symptoms.


If a person has DVT or pulmonary embolism, they may have to take anticoagulants, which are drugs that prevent blood clotting.

These may increase bleeding risk at high doses. A doctor may have to order blood tests to check clotting time and adjust the medication dosage.

Post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is a long-term complication that involves blood clot damage to the valves that help blood flow to the heart.

It can develop after a DVT episode and affect those who have received anticoagulation therapy.

Possible PTS symptoms may include:

  • leg pain
  • a feeling of heaviness in the leg
  • swelling
  • fatigue

These may worsen if a person stands or walks, but they may improve with rest.

Anyone can develop this type of blood clot. However, factors that can increase a person’s risk of developing DVT include:

  • taking birth control medications
  • being bedridden
  • sitting for long periods
  • smoking
  • being over 60 years old
  • having had DVT previously
  • fractures, injuries, or surgery that cause damage to a vein
  • hormone replacement therapy
  • pregnancy
  • chronic conditions such as heart and lung disease
  • family history of DVT

Pregnancy and DVT

Pregnant people have a higher chance of developing DVT than nonpregnant people.

According to the CDC, the risk of DVT remains higher up to 3 months after giving birth.

People with DVT should seek immediate medical attention. Without treatment, DVT can lead to pulmonary embolism, which can be fatal.

Medical professionals may use the following tests to help diagnose DVT:

  • Compression ultrasound: This imaging procedure uses sound waves to create pictures of the blood flowing in the body. It allows medical professionals to see whether there are any blood clots in the veins.
  • D-dimer test: This is a blood test that checks for the presence of D-dimer, a protein fragment that the body produces when blood clots dissolve. A D-dimer test can help determine whether a person has DVT, pulmonary embolism, or a stroke.
  • Magnetic resonance venography: This imaging procedure uses a large magnet, radio frequencies, and a computer to create pictures of a person’s veins. A medical professional may inject a dye intravenously to help visualize the veins. A doctor will typically order this test if they cannot reach a diagnosis using a compression ultrasound.

The following tests may help diagnose pulmonary embolism:

  • Computed tomography pulmonary angiography (CTPA): This test takes images of the blood vessels in the lungs to look for blood clots.
  • Ventilation-perfusion scan: This test measures the air and blood flow in the lungs. If there is a decrease in the air and blood flow, a person may have a pulmonary embolism.
  • Pulmonary angiography: This test involves inserting a tube into the blood vessels and using X-ray videos to view how blood flows to the lungs and check for clots.

These are the treatment options for people with DVT:

  • Anticoagulants: These are blood thinners, such as warfarin and heparin, that prevent blood from clotting.
  • Thrombolytics: These are drugs that healthcare professionals use to treat severe blood clots. Healthcare professionals may recommend them for those with a life threatening form of VTE, such as pulmonary embolism. This is due to the risk of bleeding that these drugs carry.
  • Vena cava filter: If a person cannot receive blood thinner therapy, the surgeon may have to insert a vena cava filter into the vein. This is used to trap blood clots before they reach the lungs to help prevent pulmonary embolism. However, it does not prevent new clots from developing.

The American College of Obstetricians and Gynecologists suggests drinking fluids, wearing loose clothes, and stretching during long trips to prevent DVT.

Compression stockings may help prevent clotting, but people should seek medical advice before wearing them.

Doctors may also prescribe medications, such as heparin and enoxaparin, to prevent clotting in those with a high risk of DVT.

Below are answers to some frequently asked questions about DVT.

What are the symptoms of DVT in the legs, knee, arm, and thigh?

DVT in the legs, knee, arm, and thigh can cause throbbing pain, swollen veins, and redness.

What are the symptoms of DVT during pregnancy?

The CDC states that people who develop blood clots during pregnancy may have limb swelling, tenderness, and discolored skin.

In the case of pulmonary embolism, they may have breathing difficulties, chest pain, and an irregular heartbeat.

Are symptoms sudden or gradual?

Venous thromboembolism does not always cause symptoms. Sometimes symptoms come on gradually. Sudden chest pain and discomfort may appear if the clot travels to the lungs.

Most people with DVT do not develop complications.

However, those who have experienced a DVT episode have a high chance of developing another clot.

DVT is more likely fatal in people with cancer or heart problems. The risk of death also increases if DVT develops into a pulmonary embolism.

DVT is when a blood clot forms in the leg, arm, or thigh. A person may experience throbbing pain, swelling, or skin discoloration.

People who smoke, have varicose veins, or take birth control drugs have an increased risk of developing blood clots, including DVT. Pregnant people also have a higher chance of developing this type of blood clot.

If a person is worried about their DVT risk, they should speak with a doctor about preventive measures and lifestyle changes that may help reduce their chances of developing a clot.