Pulmonary Embolism

A pulmonary embolism (PE) is a blood clot from your leg that travels to your lung and stays there. This causes issues with blood flow and oxygen levels in your lungs. Medications can help most people with a pulmonary embolism, but you need a prompt diagnosis and treatment. You’ll need to take medicine for several months afterward.


A blood clot becomes a pulmonary embolism when it travels from your leg to your lung.
A pulmonary embolism starts as a blood clot in your leg and moves to your lung.

What is a pulmonary embolism?

A pulmonary embolism (PE) is a blood clot in the blood vessels of your lung. This happens when a clot in another part of your body (often your leg or arm) moves through the veins to your lung. A PE restricts blood flow to your lungs, lowers oxygen levels in your lungs and increases blood pressure in your pulmonary arteries.

Without quick treatment, a pulmonary embolism can cause heart or lung damage and even death.

How serious is a pulmonary embolism?

With proper diagnosis and treatment, a PE is seldom fatal. However, an untreated PE can be serious, leading to other medical complications, including death. About 33% of people with a pulmonary embolism die before they get a diagnosis and treatment.

A pulmonary embolism can:

  • Cause damage to your lungs.
  • Cause strain on your heart, causing heart failure.
  • Be life-threatening, depending on the size of the clot.

How common is a pulmonary embolism?

Pulmonary embolism is one of the most common heart and blood vessel diseases in the world. It ranks third behind heart attack and stroke. In the United States, about 350,000 people a year get a PE.


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Symptoms and Causes

What are the warning signs of a pulmonary embolism?

The first signs of pulmonary embolism are usually shortness of breath and chest pains that get worse if you exert yourself or take a deep breath. You may cough up bloody mucus.

If you have these symptoms, get medical attention right away. Pulmonary embolism is serious but very treatable. Quick treatment greatly reduces the chance of death.

What are the symptoms of a pulmonary embolism?

Symptoms of pulmonary embolism vary, depending on the severity of the clot. Although most people with a pulmonary embolism experience symptoms, some don’t.

Pulmonary embolism symptoms may include:

  • Sudden shortness of breath — whether you’ve been active or at rest.
  • Unexplained sharp pain in your chest, arm, shoulder, neck or jaw. The pain may also be similar to symptoms of a heart attack.
  • Cough with or without bloody mucus.
  • Pale, clammy or bluish skin.
  • Rapid heartbeat (pulse).
  • Excessive sweating.
  • In some cases, feeling anxious, lightheaded, faint or passing out.
  • Wheezing.

If you have any symptoms of pulmonary embolism, get medical attention immediately.

Because you can have a blood clot and not have any symptoms, discuss your risk factors with your healthcare provider.


What causes a pulmonary embolism?

Pulmonary embolism causes include:

  • Blood collecting or “pooling” in a certain part of your body (usually an arm or leg). Blood usually pools after long periods of inactivity, such as after surgery or bed rest.
  • Injury to a vein, such as from a fracture or surgery (especially in your pelvis, hip, knee or leg).
  • Another medical condition, such as cardiovascular disease (including congestive heart failure, atrial fibrillation, heart attack or stroke).
  • An increase or decrease in your blood’s clotting factors. Elevated clotting factors can occur with some types of cancer or in some people taking hormone replacement therapy or birth control pills. Abnormal or low clotting factors may also happen as a result of blood clotting disorders.

Who is at risk for a pulmonary embolism?

People at risk of developing a PE include those who:

  • Have a blood clot in their leg, or deep vein thrombosis (DVT).
  • Are inactive for long periods of time while traveling via motor vehicle, train or plane (such as a long, cross-country car ride).
  • Have recently had trauma or injury to a vein, possibly after a recent surgery, fracture or from varicose veins.
  • Are taking birth control pills (oral contraceptives) or hormone replacement therapy.
  • Currently smoke.
  • Have a history of heart failure or stroke.
  • Have overweight (a Body Mass Index or BMI greater than 25)/obesity (a BMI greater than 30).
  • Are pregnant or have given birth in the previous six weeks.
  • Received a central venous catheter through their arm or leg.

If you have any of these risk factors and you’ve had a blood clot, talk with your healthcare provider so they can take steps to reduce your risk.

Diagnosis and Tests

How is a pulmonary embolism diagnosed?

A provider will use the following tests to make a PE diagnosis:

  • Blood tests (including the D-dimer test).
  • Computed tomography (CT) angiogram.
  • Ultrasound of your leg. (This helps identify blood clots in people’s legs, or deep vein thrombosis, which can move to the lungs and become a PE and cause more damage.)
  • A ventilation/perfusion (V/Q) scan, if you’re unable to get contrast for a CT scan. (This is a nuclear scan that can detect clots in your lung.)

Other tests your provider may order include:


Management and Treatment

How is a pulmonary embolism treated?

Healthcare providers usually treat a PE in a hospital, where they can monitor your condition closely.

The length of your pulmonary embolism treatment and hospital stay will vary, depending on the severity of the clot.

The main treatment for a PE is an anticoagulant (blood thinner).

Depending on the severity of your clot and its effect on your other organs such as your heart, you may also undergo thrombolytic therapy, surgery or interventional procedures to improve blood flow in your pulmonary arteries.

Anticoagulant medications

In most cases, treatment consists of anticoagulant medications (blood thinners). Anticoagulants decrease your blood’s ability to clot. This prevents future blood clots.

As with any medicine, it’s important to understand how and when to take your anticoagulant and follow your provider’s guidelines.

Your diagnosis will determine the type of medication you’ll take, how long you need to take it, and the type of follow-up monitoring you’ll need. Be sure to keep all scheduled follow-up appointments with your provider and the laboratory so they can monitor your response to the medication.

While taking anticoagulants, your follow-up will include frequent blood tests (prothrombin time test) to see how fast your blood clots. This helps your provider know if you’re taking the right dose.

Compression stockings

Compression stockings (support hose) improve blood flow in your legs. People with deep vein thrombosis often use them. You should use them as your provider prescribes. The stockings are usually knee-high length and compress your legs to prevent your blood from pooling.

Talk with your provider about how to use your compression stockings, for how long and how to care for them. It’s important to wash compression stockings according to directions to prevent damaging them.


If a PE is life-threatening, or if other treatments aren’t effective, your provider may recommend using surgery or a catheter to remove the blood clot from your pulmonary artery. Thrombolytic therapy (next section) is another option.

Thrombolytic therapy

Thrombolytic medications (“clot busters”), including tissue plasminogen activator (TPA), dissolve the clot. People always receive thrombolytics in the intensive care unit (ICU) of a hospital where a provider can monitor them. You may receive this type of medication if you have a special situation, such as low blood pressure or an unstable condition because of the pulmonary embolism.

Side effects of the treatment

Bleeding is a possible side effect of medications for pulmonary embolism treatment. A provider will give you the dose of anticoagulants or thrombolytics that fits your situation. Keeping you in the hospital allows them to monitor your condition.


How can I prevent a pulmonary embolism?

Ways to prevent a pulmonary embolism include:

  • Exercise regularly. If you can’t walk around, move your arms, legs and feet for a few minutes every hour. If you know you’ll need to sit or stand for long periods, wear compression stockings to encourage blood flow.
  • Drink plenty of fluids, but limit alcohol and caffeine.
  • Don’t use tobacco products.
  • Avoid crossing your legs.
  • Don’t wear tight-fitting clothing.
  • Lose weight if you have overweight.
  • Elevate your feet for 30 minutes twice a day.
  • Talk to your provider about reducing your risk factors, especially if you or any of your family members have had a blood clot.

Your provider may also recommend an interventional procedure in which a healthcare provider places a filter inside your body’s largest vein. A vena cava filter traps clots before they enter your lungs.

Outlook / Prognosis

What can I expect if I have a pulmonary embolism?

Without treatment, a pulmonary embolism is a very serious condition that can lead to permanent illness or death. With treatment, your prognosis depends on the size of the blood clot and blockages, as well as your overall health and how well your heart can pump blood.

Will a pulmonary embolism go away?

It can take months or years for a pulmonary embolism to go away completely. Repeated PE or a very large PE can lead to pulmonary hypertension in some people.

Living With

How do I take care of myself?

You’ll need to take a blood thinner for three to six months or longer. Don’t stop taking this unless your provider instructs you to. If you’re taking a blood thinner, don’t do things that have a high risk of an injury that could make you bleed.

Be sure you discuss and understand your follow-up care with your healthcare provider. Follow their recommendations to reduce the risk of another PE.

Keep all appointments with your provider and the laboratory so they can monitor your response to prescribed treatments.

When should I see my healthcare provider?

See your healthcare provider for follow-up appointments. While taking a blood thinner, contact your provider if you have black poop, a bad headache or a bruise that’s getting bigger. These could mean that you’re bleeding.

When should I go to the ER?

Get immediate treatment if you have pulmonary embolism symptoms. (See symptoms section above.)

What questions should I ask my doctor?

  • What’s the best treatment for me?
  • How long do I need to take the medicine you prescribe?
  • When is my first follow-up appointment?

A note from Cleveland Clinic

Treatments help many people with a pulmonary embolism, but it’s important to get a quick diagnosis and treatment. Be on the lookout for symptoms if you have risk factors for a PE and do what you can to prevent one. If you do get a pulmonary embolism, get help quickly.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 12/13/2022.

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