The presence of a blood clot in the lung that causes a partial or complete blockage is called a pulmonary embolism. The blood clot usually travels from another part of the body, most commonly a vein in the leg, and deposits itself in an artery in the lung. The pulmonary arteries carry blood from the heart to the lungs. When the arteries are blocked by a blood clot, adequate oxygen cannot be provided to the body. A pulmonary embolism is a serious, life-threatening condition.
Causes
In 90 percent of cases, a pulmonary embolism is a complication of another condition called deep vein thrombosis, which is the presence of blood clots in the veins of the leg. The blood clot breaks free from the veins in the leg and travels through the bloodstream until it reaches the lungs, where it can cause a blockage in the artery, according to the National Heart, Lung and Blood Institute. It is rare that only a single clot will be present. In most cases, the pulmonary arteries will be blocked by several clots.
Symptoms
The most common symptoms associated with a blood clot in the lung are shortness of breath, chest pain and a bloody cough. Other symptoms include wheezing, leg swelling, clammy and discolored skin, excessive sweating, irregular heartbeat, weak pulse and lightheadedness. Occasionally, feelings of anxiety or dread will accompany a pulmonary embolism.
Tests
A blood clot in the lung can be difficult to diagnose and usually requires a series of tests. The first types of tests are a chest X-ray and a spiral CT scan, which takes pictures of the heart and lungs. Although pulmonary embolisms cannot usually be seen on a chest X-ray, the test can rule out underlying heart or lung diseases. Spiral CT scans can show actual blockages caused by blood clots. A lung scan is another type of testing method that uses small amounts of radioactive material to study airflow and blood flow, according to Mayo Clinic. A blood clot in the lung will show a blockage in airflow and blood flow. A pulmonary angiogram is the most accurate way to diagnose a pulmonary embolism. During the procedure, a thin tube is inserted into a vein and threaded to the pulmonary arteries. A special dye is then injected to look for the presence of a blood clot.
Treatment
Treatment for a pulmonary embolism includes medication and possible surgery. Medications available are anticoagulants and clot dissolvers. Anticoagulants can be injected with a needle or taken orally and work by preventing new clots from forming. Clot dissolvers work by dissolving existing clots quickly. They are only used in life-threatening situations because they can cause severe bleeding. Available surgical procedures include clot removal and a vein filter. A clot removal procedure uses a thin tube to remove the clot. A vein filter is physically inserted into a vein and blocks clots from being carried to the lungs.
Complications
A blood clot in the lung is a serious condition and requires immediate medical treatment. If left untreated, a pulmonary embolism can lead to pulmonary hypertension, which is a condition characterized by high blood pressure in the lungs. The increased pressure that must be exerted by the heart can wear out the cardiac tissue and result in future heart problems. An untreated pulmonary embolism can also be life-threatening. Approximately one-third of people with an undiagnosed or untreated blood clot in the lungs die, according to Mayo Clinic.
