Medically Reviewed By William C. Lloyd III, MD, FACS

What is an embolism?

An embolism, also called thromboembolism, is a blockage in one of the arteries of the body due to a blood clot that has broken off from another location in the body (embolus) and traveled through the bloodstream to lodge in a small blood vessel. The blockage may limit or stop blood flow. An embolism may be serious and life threatening.

Deep vein thrombosis is the primary cause of embolism. In deep vein thrombosis, blood clots form in the large veins of the legs. Sometimes a blood clot breaks free and is carried through the bloodstream. It may then cause an embolism by blocking an artery in the lungs, brain, or other organs.

Symptoms of embolism vary greatly depending on the severity and location of the embolism. Some individuals with embolism have no symptoms. An embolism in the lungs is called a pulmonary embolism. An embolism in the brain can cause a stroke. An embolism in the coronary vessels that supply the heart can cause a heart attack.

Treatment of embolism aims to dissolve, remove, or limit the growth of the blood clot, and prevent the formation of future emboli. This may be achieved through medication, minimally invasive procedures, or, rarely, surgery.

An embolism may be life threatening. Seek immediate medical care (call 911) for serious symptoms, such as altered vision, chest pain, fainting, palpitations, sweating, or severe difficulty breathing, or if you think you may be having a heart attack or stroke.

What are the symptoms of an embolism?

Symptoms of an embolism vary with the severity and location of the embolism. It is possible to have an embolism without any symptoms.

At times, any of these embolism symptoms can be severe and may indicate a life-threatening condition, such as pulmonary embolism, heart attack, or stroke.

Symptoms of an embolism in the arms or legs

Symptoms of an embolism in an extremity such as the hands, arms, legs or feet include:

Serious symptoms that might indicate a life-threatening condition

In some cases, an embolism can be life threatening. If the embolism occurs in the lungs, it may cause a life-threatening pulmonary embolism. An embolism can also cause a heart attack or stroke. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms of pulmonary embolism including:

What causes an embolism?

An embolism is a blockage in one of the arteries of the body due to a circulating blood clot. Blockage of an artery may restrict blood flow to a limb, the lung or another organ.

Primary cause of embolism

The primary cause of embolism is deep vein thrombosis, a condition in which blood clots form in the large veins of the lower extremities, such as in the thigh or lower leg. If the blood clot breaks free from the wall of the vein, it can travel through the bloodstream and cause an embolism by blocking an artery.

Other causes of embolism

Other causes of blood clot formation and embolism include:

What are the risk factors for embolism?

A number of factors increase the risk of developing an embolism. Not all people with risk factors will get an embolism. Risk factors for an embolism include:

  • Abnormal vascular anatomy (inferior vena cava anomalies)

  • Advanced age

  • Atrial fibrillation 

  • Cancer

  • Central venous catheters 

  • Deep vein thrombosis (blood clot in the leg that can break loose from the leg and cause a pulmonary embolism in the lung, a heart attack, or stroke)

  • Diabetes

  • Hypercholesterolemia

  • Hypercoagulable states (anticoagulant deficiency)

  • Long periods of immobility, such as bed rest or prolonged air travel

  • Obesity

  • Oral contraceptives or hormone therapy

  • Pregnancy

  • Previous heart attack, embolism, or stroke

  • Recent hospitalization (any cause)

  • Recent infection

  • Recent surgery or broken bone

  • Replacement hormone therapy (menopause)

  • Smoking

How is an embolism treated?

Treatment of an embolism varies greatly depending on its severity. The underlying cause of the embolism should be identified and treated promptly. Medications are used to control the formation and growth of blood clots and to restore blood flow to the affected area of the body. More invasive procedures may be required in severe or life-threatening cases of embolism, or if the blood clot is very large.

Medications used to treat embolism

Depending on the underlying cause and severity of your embolism, your doctor may prescribe the following medications:

  • Anticoagulants such as warfarin (Coumadin), heparin, and thrombin inhibitors, which thin the blood and prevent the formation or growth of blood clots

  • Antiplatelet medications such as aspirin and clopidogrel (Plavix), which prevent the formation of new clots

  • Painkillers and sedatives, which can make you more comfortable

  • Thrombolytics, which quickly dissolve large blood clots in severe or life-threatening cases of embolism

Procedures to treat embolism

If blood flow is completely or almost completely blocked, your heath care provider may recommend one of the following procedures:

  • Angioplasty, in which the blocked blood vessel is widened by inflating a balloon-like catheter in the vessel. A small mesh tube called a stent may be placed inside the blood vessel to keep it open.

  • Arterial bypass, in which the blocked artery is bypassed with a vessel harvested from another part of your body or with manufactured tubing.

  • Embolectomy, in which the blood clot is removed with a catheter or open surgery. A catheter is a flexible tube inserted into a vein in the upper thigh or arm and then guided though the veins to reach the blood clot.

  • Intravenous filter placement to stop future clots from traveling upstream.

What are the potential complications of an embolism?

Left untreated, an embolism may lead to serious, even life-threatening complications. You can help minimize your risk of serious complications by following the treatment plan you and your health care professional design specifically for you. Complications of embolism include:

  • Amputation

  • Hypoxia (low levels of oxygen in the blood)

  • Myocardial infarction (heart attack)

  • Organ failure or dysfunction

  • Serious infections and gangrene

  • Shock

  • Stroke

  • Sudden death

Was this helpful?
  1. Pulmonary Embolism. JAMA Patient Page. http://jama.ama-assn.org/content/295/2/240.full.pdf
  2. Pulmonary Embolism. National Heart, Lung, and Blood Institute Diseases and Conditions Index. http://www.nhlbi.nih.gov/health/dci/Diseases/pe/pe_what.html
  3. Tierney LM Jr., Saint S, Whooley MA (Eds.) Current Essentials of Medicine (4th ed.). New York: McGraw-Hill, 2011.
  4. Goldhaber SZ. Risk factors for venous thromboembolism. J Am Coll Cardiol 2010; 56:1.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 9
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