What is Pulmonary Embolism?

A pulmonary embolism is a blood clot that blocks and stops blood flow to an artery in the lung. In most cases, the blood clot starts in a deep vein in the leg and travels to the lung. A clot rarely forms in a vein elsewhere in the body.

What Causes Pulmonary Embolism?

Blood clots can form in the arteries and veins. Clots that form in the veins are called venous clots. Leg veins can be superficial veins (close to the skin surface) or deep veins (close to bone and surrounded by muscle). Venous clots most often occur in the deep veins of the legs. This is called deep vein thrombosis (DVT). When a clot forms in the deep veins of the leg, there is the potential for some of the clot to break off and travel through the blood to another part of the body, usually the lungs. DVT is the most common cause of pulmonary embolism.

Other less common sources of pulmonary embolism are fat embolism (usually associated with a fracture of a large bone), amniotic fluid embolism, air bubbles, and deep vein thrombosis in the upper body. Clots can also form at the tip of an indwelling intravenous (IV) catheter, break off and travel to the lungs. What Are the Symptoms of Pulmonary Embolism? Each person may experience symptoms differently. The most common symptoms are: Sudden shortness of breath (most common) Chest pain (usually worse when breathing) Feeling anxious Feeling dizzy, lightheaded, or fainting Irregular heartbeat Palpitations Spitting up blood or coughing Sweating Low blood pressure Also deep vein thrombosis ( Pain in the affected leg (may only be when standing or walking) swelling in the leg Pain, redness or warmth in the leg(s) Redness and/or discolored skin

How is Pulmonary Embolism Treated?

In treatment, blood thinners (anticoagulant) drugs are used that reduce the blood's ability to clot. These drugs are used to stop the growth of the clot and prevent clot formation. Blood thinners can be given by pill, subcutaneously or by injection (intravenously). Treatment usually takes 3-6 months.

Treatment is planned longer in cases with pre-existing blood clots. In patients receiving treatment for another disease such as cancer, blood thinners are continued as long as the pulmonary embolism risk factor persists. Treatment can sometimes be continued for life, especially in people with a genetic predisposition to clot formation. When a pulmonary embolism is life-threatening, hospital treatments are used to remove or break up the clot.

Medicines called thrombolytics are medicines that can quickly dissolve a blood clot. They are used to treat large blood clots that cause severe complaints. In some cases, a tube called a catheter is used to reach the blood clot. Rarely, surgery may be required.