A pulmonary embolism is a blood clot that travels
to the lungs. Often, the clot forms in another part of the body, usually in
the veins of the legs. Large clots can be fatal. The January 11, 2006, issue
of JAMA includes an article about diagnosing pulmonary
embolism. This Patient Page is based on one previously published in the December
3, 2003, issue of JAMA.
Symptoms and signs of pulmonary embolism
Risk factors for pulmonary embolism
Long periods of immobility (such as bed rest because of an illness)
Taking oral contraceptives
Previous stroke or heart attack
Diagnosis of pulmonary embolism
Pulmonary embolism can be difficult to diagnose because the symptoms
are broad and resemble those of other diseases. Results of the patient's history
and physical examination are very important. Some other tests that may be
Arterial blood gases—measurement of oxygen and carbon dioxide
levels in the blood
D-dimer assay—a blood test for evidence of blood clots
Ultrasound of the legs—sound wave images to detect blood
clots in the veins
Spiral computed tomography—detailed computerized x-ray imaging
Lung scan—test of blood flow through the lungs
Pulmonary arteriogram—injections to show the arteries in
the lungs to detect blood clots
Immediate treatment usually includes giving injectable anticoagulants (blood thinners)—such as heparin, followed by warfarin (an anticoagulant taken
by mouth)—to stabilize the clot, prevent additional clots, and restore
normal blood flow in the lungs. Oxygen and sedatives may be given to make
the patient more comfortable. If the clot is large, thrombolytic ("clot busting") drugs may be needed to remove it.
To find this and other JAMA Patient Pages, go to the Patient Page link
on JAMA's Web site at http://www.jama.com.
A previous Patient Page on thrombophlebitis was published in the August 10,
Sources: American Heart Association; National Heart, Lung, and Blood
The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate
in most instances, but they are not a substitute for medical diagnosis. For
specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied
noncommercially by physicians and other health care professionals to share
with patients. To purchase bulk reprints, call 718/946-7424.
TOPIC: LUNG DISEASE
This article was corrected on 1/16/06, prior to publication of the correction in print.