Deep Vein Thrombosis and Pulmonary Embolism

A pulmonary embolism is a blood clot that blocks blood flow to a blood vessel in the lung. This may lead to lowered oxygen levels in the lungs and increased pressure in the pulmonary artery. Thus, it can be life-threatening. In most cases, the blood clot starts in a vein in the leg that travels to the lung. Venous clots often occur in the deep veins of the legs, referred to as deep vein thrombosis (DVT). Blockages in the blood vessels may also be caused by other substances, including fat from a long bone that is broken, a part of tumor tissue, or air bubbles.

Prompt treatment of pulmonary embolism greatly reduces the risk of death. Preventing blood clots in the legs will also help protect against pulmonary embolism.

• Past history of blood clots or pulmonary embolism
• Family history of blood clots or pulmonary embolism
• Heart disease (i.e., heart failure)
• Cancer or cancer treatments
• Recent surgery (or bone fracture)
• Clotting disorders
• COVID-19
• Prolonged bedrest
• Prolonged immobilization (i.e., long plane/car trips)
• Smoking
• Overweight
• Pregnancy or postpartum (up to 3 months after the delivery)
• Supplemental estrogen (e.g., oral contraceptives, hormone replacement therapy)
• Varicose veins
• Indwelling (IV) intravenous catheter
• Hospitalizations
• Severe trauma

• Leg pain
• Leg swelling
• Leg redness or discoloration, or warmth around the leg

• Sudden shortness of breath
• New shortness of breath with exertion
• Chest pain or discomfort, and especially if worse with deep breath
• Lightheadedness or dizziness
• Fainting
• Rapid pulse
• Rapid breathing
• Coughing up blood

*Pulmonary Embolism is a life-threatening complication of deep vein thrombosis — seek emergency medical right away if suspected.

• D-dimer test (blood test)
• Computed tomography (CT) angiogram <Image of CTPA>
• Ultrasound of the leg (i.e., to diagnose DVT) <Image of ultrasound>
• A ventilation/perfusion (V/Q) scan

Other tests your provider may order include:

• Pulmonary angiogram (if necessary)
• Chest X-ray
• Pulse oximetry (to measure the amount of oxygen in your blood)
• Echocardiogram (to assess any strain on the heart or clots in the heart)

• Anticoagulant medications
• Thrombolytic medications (to dissolve blood clots)
• Surgery or other interventional procedures (i.e., thrombectomy) for clot removal
• Vena cava filter

Preventing clots in the deep leg veins will help prevent DVT and pulmonary embolisms. Preventive measures include the following:

• Anticoagulants – If necessary, these may be given to people at risk for clotting (e.g., after surgery).
• Compression stockings– This is especially important if you’ll need to sit or stand for long periods to encourage blood flow.
• Physical activity – This is important after surgery to prevent prolonged immobilization. It is also important during prolonged traveling to move about and walk around.
• Pneumatic compression
• Avoid tobacco products
• Lose weight if overweight
• Exercise
• Know your risks
• Know your family history
• Recognize signs and symptoms of blood clots