Pulmonary Embolism

A pulmonary embolism (PE) is a blood clot in your lung that creates a blockage. This causes issues with blood flow and oxygen levels in your lungs. A PE is a medical emergency. You need a prompt diagnosis and treatment.


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 one of the blood vessels in your lung. This happens when a clot in another part of your body (often your leg or arm) moves through your 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.

This condition is a medical emergency. Without quick treatment, a pulmonary embolism can cause heart or lung damage and even death. About 33% of people with a pulmonary embolism die before they get a diagnosis and treatment.

A pulmonary embolism can:

  • Damage your lungs.
  • Put strain on your heart, causing heart failure.
  • Be life-threatening, depending on the size of the clot.

With timely diagnosis and treatment, a PE is seldom fatal.

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 900,000 people a year get a PE.


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Symptoms and Causes

What are the symptoms 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.

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.

Pulmonary embolism symptoms can 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.
  • Fast breathing.
  • Wheezing.
  • Unexplained sharp pain in your chest, arm, back, shoulder, neck or jaw. The pain may be similar to symptoms of a heart attack and can get worse when you take a breath.
  • 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.

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

How long can you have a pulmonary embolism without knowing?

Some people have mild symptoms that appear over a number of days or even weeks. Over time, the symptoms get worse and get your attention. But some people get symptoms just minutes (or even seconds) after a pulmonary embolism happens.

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, like after surgery, bed rest or a long flight or plane ride.
  • Injury to a vein, like from a fracture or surgery (especially in your pelvis, hip, knee or leg).
  • Another medical condition, like 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.

What are the risk factors 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 from surgery, a fracture or varicose veins.
  • Are using hormonal-based contraception (like birth control pills, patches or rings) or hormone replacement therapy.
  • Have a blood clotting disorder.
  • Have a family history of blood clots.
  • Currently smoke.
  • Have diabetes.
  • Have cancer.
  • Are older than 60.
  • Have a history of heart failure, heart attack or stroke.
  • Have overweight (a body mass index or BMI greater than 25) or 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 of PE.


What are the complications of a pulmonary embolism?

A pulmonary embolism can lead to:

Diagnosis and Tests

How is a pulmonary embolism diagnosed?

After looking at your symptoms and risk factors, a provider will use the following tests to make a PE diagnosis:

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. Some people may not need to stay overnight.

The main treatment for a pulmonary embolism 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 may 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 working, your provider may recommend using surgery or a catheter to remove the blood clot from your pulmonary artery. Thrombolytic therapy is another option. Your healthcare provider may also recommend an interventional procedure in which a provider places a filter inside your body’s largest vein. A vena cava filter traps clots before they enter your lungs.

Thrombolytic therapy

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

Complications/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 soon after treatment will I feel better?

You should feel better within a week of treatment. But a pulmonary embolism can take months or years to go away completely.

Your heart has to work harder to push against restricted blood flow and higher blood pressure from a PE. Because of this, some people also have issues with getting one of their heart chambers back to normal months later. This makes them less able to handle as much physical activity as they did before they had a pulmonary embolism.


Can a pulmonary embolism be prevented?

Yes, you may be able to prevent it. Ways to prevent a pulmonary embolism include:

  • Getting regular physical activity. 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.
  • Drinking plenty of fluids, but limiting alcohol and caffeine.
  • Not using tobacco products.
  • Avoiding crossing your legs.
  • Not wearing tight-fitting clothing.
  • Getting to a weight that’s healthy for you.
  • Elevating your feet for 30 minutes twice a day.
  • Talking to your provider about reducing your risk factors, especially if you or any of your family members have had a blood clot.
  • Talking to your provider about a vena cava filter.

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. Some people die suddenly or a few hours after a pulmonary embolism happens. This can happen before a provider makes a diagnosis.

Your risk of dying from a PE is higher if you have a heart or lung condition. Still, with better imaging methods than providers had in the past, a pulmonary embolism is fatal for only about 1% to 3% of people who have one.

With treatment, your prognosis (outlook) 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. Chronic thromboembolic pulmonary hypertension (CTEPH) is a chronic manifestation of PEs that keep coming back.

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 it unless your provider instructs you to. If you’re taking a blood thinner, don’t do things that put you at 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. They may suggest you stop using tobacco products, get more physical activity and eat more fruits and vegetables.

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

If you’re feeling anxious or fearful after your PE, ask your provider about talking to a counselor who can help.

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 signs could mean that you’re bleeding internally.

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?

Questions you may want to ask your provider include:

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

A note from Cleveland Clinic

After you survive a pulmonary embolism, you may be surprised to find that your life may not just go back to the way it was before. It’s OK to admit that you’ve been through something difficult. People might not understand why you’re afraid it’ll happen again. It can help to talk through your fears with a support group or a counselor. To fight your fears, keep following your provider’s recommendations. That includes taking medicines they prescribe for you.

Medically Reviewed

Last reviewed on 02/20/2024.

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