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Pulmonary embolus - Overview

Alternative Names

Venous thromboembolism; Lung blood clot; Blood clot - lung; Embolus; Tumor embolus

Definition of Pulmonary embolus:

A pulmonary embolus is a blockage of an artery in the lungs by fat, air, a blood clot, or tumor cells.

Causes, incidence, and risk factors:

A pulmonary embolus is most often caused by a blood clot in a vein, especially a vein in the leg or in the pelvis (hip area). The most common cause is a blood clot in one of the deep veins of the legs. This type of clot is called a deep vein thrombosis (DVT).

Less common causes include air bubbles, fat droplets, amniotic fluid, or clumps of parasites or tumor cells, all of which may lead to a pulmonary embolus.

Risk factors for a pulmonary embolus include:

Burns
Cancer
Childbirth
Family history of blood clots
Fractures of the hips or femur
Heart attack
Heart surgery
Long-term bed rest or staying in one position for a long time, such as a long plane or car ride
Severe injury
Stroke
Surgery (especially orthopedic or neurological surgery)
Use of birth control pills or estrogen therapy

People with certain clotting disorders may also have a higher risk.

Lungs

Respiratory system

Pulmonary embolus

Reviewed last on: 1/27/2009
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

References

Anderson DR, Kahn SR, Rodger MA, et al. Computed tomographic pulmonary angiography vs ventilation-perfusion lung scanning in patients with suspected pulmonary embolism: a randomized controlled trial.JAMA. 2007;298(23):2743-53.

Righini M, Le Gal G, Aujesky D, et al. Diagnosis of pulmonary embolism by multidetector CT alone or combined with venous ultrasonography of the leg: a randomised non-inferiority trial. Lancet. 2008;371(9621):1343-52.

Snow V, Qaseem A, Barry P, et al. Management of venous thromboembolism: a clinical practice guideline from the American College of Physicians and the American Academy of Family Physicians. Ann Intern Med. 2007;146(3):204-10. Epub 2007 Jan 29.

Tapson VF. Pulmonary embolism. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 99.

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