Topic Overview

What is pulmonary embolism?

Pulmonary embolism is the sudden blockage of a major blood vessel (artery) in the lung, usually by a blood clot. In most cases, the clots are small and are not deadly, but they can damage the lung. But if the clot is large and stops blood flow to the lung, it can be deadly. Quick treatment could save your life or reduce the risk of future problems.

What are the symptoms?

The most common symptoms are:

• Sudden shortness of breath.
• Sharp chest pain that is worse when you cough or take a deep breath.
• A cough that brings up pink, foamy mucus.

Pulmonary embolism can also cause more general symptoms. For example, you may feel anxious or on edge, sweat a lot, feel lightheaded or faint, or have a fast heart rate or palpitations.

If you have symptoms like these, you need to see a doctor right away, especially if they are sudden and severe.

What causes pulmonary embolism?

In most cases, pulmonary embolism is caused by a blood clot in the leg that breaks loose and travels to the lungs. A blood clot in a vein close to the skin is not likely to cause problems. But having blood clots in deep veins (deep vein thrombosis) can lead to pulmonary embolism. More than 300,000 people each year have deep vein thrombosis or a pulmonary embolism.¹

Other things can block an artery, such as tumors, air bubbles, amniotic fluid, or fat that is released into the blood vessels when a bone is broken. But these are rare.

What increases your risk of pulmonary embolism?

Anything that makes you more likely to form blood clots increases your risk of pulmonary embolism. Some people are born with blood that clots too quickly. Other things that can increase your risk include:

• Being inactive for long periods. This can happen when you have to stay in bed after surgery or a serious illness, or when you sit for a long time on a flight or car trip.
• Recent surgery that involved the legs, hips, belly, or brain.
• Some diseases, such as cancer, heart failure, stroke, or a severe infection.
• Pregnancy and childbirth (especially if you had a cesarean section).
• Taking birth control pills or hormone therapy.
• Smoking.

You are also at higher risk for blood clots if you are an older adult (especially older than 70) or extremely overweight (obese).