Health Topics for Respiratory Problems

Department of Respiratory Care

Lung Cancer Program

Interstitial Lung Disease -- Department of Internal Medicine

Allergies

Pulmonary embolism

Pulmonary embolism is caused by a blood clot that blocks an artery in the lung. It can be fatal if it cuts off the blood supply to a large part of the lung. Pulmonary emboli strike about 600,000 Americans each year. About 10 percent of people diagnosed with a pulmonary embolism die within the first hour so rapid diagnosis and treatment are very important.

Most blood clots start as small clots originating in the legs that come loose. The clot travels upwards in the veins, through the heart, and goes into the blood vessels in the lungs. The blood vessels in the lungs get smaller and smaller and the clot finally stops where the blood vessel is so small that the clot obstructs the flow of blood to a part of the lung. Depending on where the clot stops and how large the clot is, the part of the lung that has lost its blood supply will no longer function. Rarely, the clot (or embolus) is made up of fat or tumor cells.

Many cases occur among people already hospitalized for other reasons. A person is more likely to have clots after surgery, stroke, long-term bed rest or inactivity, or fractures of the hip or legs. There is a somewhat higher risk among overweight people and during pregnancy. There is also an increased risk among women who take birth control pills and those who smoke cigarettes.

If a clot lodges in the lungs, there may be sudden shortness of breath, chest pain, coughing up blood, and a low-grade fever. The patient sometimes tightens the chest muscles or avoids deep breathing to diminish pain. The patient may also have some swelling in the legs. A person with a large clot may pass out, appear bluish in color, or have bulging neck veins.

Most clots resolve after 10 to 14 days. Treatment consists of oxygen therapy and blood thinners that prevent further blood clots. Patients with large clots may need agents that break up the clot. Extreme cases may require emergency surgery.

Anyone recovering from pulmonary embolism, or who is at high risk of having one, often takes medications that thin the blood for several months. They should consult their healthcare provider before taking any other drugs or before engaging in strenuous activities. Keeping as active as possible is the best prevention.

Prevention tips include:

• avoid standing in one position for a long time
• avoid wearing anything on the legs that restricts the return of blood from the feet to the heart (such as knee high hose that have an elastic band at the top of them)
• avoid crossing your legs when sitting for an extended period
• take breaks to move your legs on long trips
• walk as soon as possible after surgery (You may need support hose when you walk for a while.)
• if confined to bed, exercise by pushing feet against a board
• elevate your legs now and then
• wear support stockings if advised by your healthcare provider
• follow a low fat diet
• do not smoke
• stay fit and
• keep active

Last Reviewed 2005

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

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