Pulmonary Embolism

A pulmonary embolism is a sudden blockage in a lung artery.

The cause is usually a blood clot in the leg called a deep vein thrombosis that breaks loose and travels through the bloodstream to the lung. 

Pulmonary embolism is a serious condition that can cause

  • Permanent damage to the affected lung
  • Low oxygen levels in your blood
  • Damage to other organs in your body from not getting enough oxygen

If a clot is large, or if there are many clots, pulmonary embolism can cause death.

Half the people who have pulmonary embolism have no symptoms. If you do have symptoms, they can include shortness of breath, chest pain or coughing up blood. Symptoms of a blood clot include warmth, swelling, pain, tenderness and redness of the leg. The goal of treatment is to break up clots and help keep other clots from forming.

Preventing pulmonary embolism (PE) begins with preventing deep vein thrombosis (DVT). Knowing whether you're at risk for DVT and taking steps to lower your risk are important.

  • Exercise your lower leg muscles if you're sitting for a long time while traveling.
  • Get out of bed and move around as soon as you're able after having surgery or being ill. The sooner you move around, the better your chance is of avoiding a blood clot.
  • Take medicines to prevent clots after some types of surgery (as your doctor prescribes).
  • Follow up with your doctor.

If you've already had DVT or PE, you can take more steps to prevent new blood clots from forming. Visit your doctor for regular checkups. Also, use compression stockings to prevent chronic (ongoing) swelling in your legs from DVT (as your doctor advises).

Contact your doctor right away if you have any signs or symptoms of DVT or PE.

 

Pulmonary embolism (PE) occurs equally in men and women. The risk increases with age. For every 10 years after age 60, the risk of having PE doubles.

Certain inherited conditions, such as factor V Leiden, increase the risk of blood clotting and PE.

Major Risk Factors

Your risk for PE is high if you have deep vein thrombosis (DVT) or a history of DVT. In DVT, blood clots form in the deep veins of the body—most often in the legs. These clots can break free, travel through the bloodstream to the lungs, and block an artery.

Your risk for PE also is high if you've had the condition before.

Other Risk Factors

Other factors also can increase the risk for PE, such as:

  • Being bedridden or unable to move around much
  • Having surgery or breaking a bone (the risk goes up in the weeks following the surgery or injury)
  • Having certain diseases or conditions, such as a stroke, paralysis (an inability to move), chronic heart disease, or high blood pressure
  • Smoking

People who have recently been treated for cancer or who have a central venous catheter are more likely to develop DVT, which increases their risk for PE. A central venous catheter is a tube placed in a vein to allow easy access to the bloodstream for medical treatment.

Other risk factors for DVT include sitting for long periods (such as during long car or airplane rides), pregnancy and the 6-week period after pregnancy, and being overweight or obese. Women who take hormone therapy pills or birth control pills also are at increased risk for DVT.

The risk of developing blood clots increases as your number of risk factors increases.

 

Major Causes

Pulmonary embolism (PE) usually begins as a blood clot in a deep vein of the leg. This condition is called deep vein thrombosis. The clot can break free, travel through the bloodstream to the lungs, and block an artery.

Blood clots can form in the deep veins of the legs if blood flow is restricted and slows down. This can happen if you don't move around for long periods, such as:

  • After some types of surgery
  • During a long trip in a car or airplane
  • If you must stay in bed for an extended time

Blood clots are more likely to develop in veins damaged from surgery or injured in other ways.

Other Causes

Rarely, an air bubble, part of a tumor, or other tissue travels to the lungs and causes PE. Also, if a large bone in the body (such as the thigh bone) breaks, fat from the bone marrow can travel through the blood. If the fat reaches the lungs, it can cause PE

 

Major Signs and Symptoms

Signs and symptoms of pulmonary embolism (PE) include unexplained shortness of breath, problems breathing, chest pain, coughing, or coughing up blood. An arrhythmia (irregular heartbeat) also may suggest that you have PE.

Sometimes the only signs and symptoms are related to deep vein thrombosis (DVT). These include swelling of the leg or along a vein in the leg, pain or tenderness in the leg, a feeling of increased warmth in the area of the leg that's swollen or tender, and red or discolored skin on the affected leg.

See your doctor right away if you have any signs or symptoms of PE or DVT. It's also possible to have PE and not have any signs or symptoms.

Other Signs and Symptoms

Some people who have PE have feelings of anxiety or dread, light-headedness or fainting, rapid breathing, sweating, or an increased heart rate.

Medical History and Physical Exam

To diagnose PE, the doctor will ask about your medical history. He or she will want to:  

  • Find out your deep vein thrombosis (DVT) and PE risk factors
  • See how likely it is that you could have PE
  • Rule out other possible causes for your symptoms

Your doctor also will do a physical exam. During the exam, he or she will check your legs for signs of DVT. He or she also will check your blood pressure and your heart and lungs.

Diagnostic Tests

Many tests can help diagnose PE. Which tests you have will depend on how you feel when you get to the hospital, your risk factors, available testing options, and other conditions you could possibly have. You may have one or more of the following tests.

Doctors can use ultrasound to look for blood clots in your legs. If the doctor finds blood clots in the deep veins of your legs, he or she will recommend treatment.

DVT and PE both are treated with the same medicines.

Certain blood tests may help your doctor find out whether you're likely to have PE. A D-dimer test measures a substance in the blood that's released when a blood clot breaks down. High levels of the substance may mean a clot is present. If your test is normal and you have few risk factors, PE isn't likely.

Other blood tests check for inherited disorders that cause blood clots. Blood tests also can measure the amount of oxygen and carbon dioxide in your blood. A clot in a blood vessel in your lungs may lower the level of oxygen in your blood.

To rule out other possible causes of your symptoms, your doctor may use one or more of the following tests.

  • Echocardiography (echo). This test uses sound waves to create a moving picture of your heart. Doctors use echo to check heart function and detect blood clots inside the heart.
  • EKG (electrocardiogram). An EKG is a simple, painless test that detects and records the heart's electrical activity.
  • Chest x ray. This test creates pictures of your lungs, heart, large arteries, ribs, and diaphragm
  • Chest MRI (magnetic resonance imaging). This test uses radio waves and magnetic fields to create pictures of organs and structures inside the body. MRI often can provide more information than an x ray.

 

Pulmonary embolism (PE) is treated with medicines, procedures, and other therapies. The main goals of treating PE are to stop the blood clot from getting bigger and keep new clots from forming.

Treatment may include medicines to thin the blood and slow its ability to clot. If your symptoms are life threatening, your doctor may give you medicine to quickly dissolve the clot. Rarely, your doctor may use surgery or another procedure to remove the clot.

Anticoagulants, or blood thinners, decrease your blood's ability to clot. They're used to stop blood clots from getting larger and prevent clots from forming. Blood thinners don't break up blood clots that have already formed.

If you have deep vein thrombosis, treatment with blood thinners usually lasts for 3 to 6 months. If you've had blood clots before, you may need a longer period of treatment. If you're being treated for another illness, such as cancer, you may need to take blood thinners as long as PE risk factors are present.

The most common side effect of blood thinners is bleeding. This can happen if the medicine thins your blood too much and can be life threatening.

Sometimes the bleeding is internal, which is why people treated with blood thinners usually have routine blood tests. These tests, called PT and PTT tests, measure the blood's ability to clot. These tests also help your doctor make sure you're taking the right amount of medicine. Call your doctor right away if you're bruising or bleeding easily.

Emergency Treatment

When PE is life threatening, a doctor may use treatments that remove or break up the blood clot. These treatments are given in an emergency room or hospital.

Thrombolytics are medicines that can quickly dissolve a blood clot. They're used to treat large clots that cause severe symptoms. Because thrombolytics can cause sudden bleeding, they're used only in life-threatening situations.

Sometimes a doctor may use a catheter (a flexible tube) to reach the blood clot. The catheter is inserted into a vein in the groin or arm and threaded to the clot in the lung. The doctor may use the catheter to remove the clot or deliver medicine to dissolve it.

Rarely, surgery may be needed to remove the blood clot.

Other Types of Treatment

If you can't take medicines to thin your blood, or if the medicines don't work, your doctor may suggest a vena cava filter. This device keeps blood clots from traveling to your lungs.

The filter is inserted inside a large vein called the inferior vena cava. (This vein carries blood from the body back to the heart). The filter catches clots before they travel to the lungs. This type of treatment can prevent PE, but it won't stop other blood clots from forming.

Graduated compression stockings can reduce the chronic swelling that a blood clot in the leg may cause.

Graduated compression stockings are worn on the legs from the arch of the foot to just above or below the knee. These stockings are tight at the ankle and become looser as they go up the leg. This causes gentle compression up the leg. The pressure keeps blood from pooling and clotting.

Pulmonary embolism (PE) usually is treated in a hospital. After leaving the hospital, you may need to take medicine at home for 6 months or longer.

It's important to:

  • Take all medicines as prescribed, and have blood tests done as your doctor advises.
  • Talk with your doctor before taking blood-thinning medicines with any other medicines, including over-the-counter products. Over-the-counter aspirin, for example, can thin your blood. Taking two medicines that thin your blood may increase your risk of bleeding.
  • Ask your doctor about your diet. Foods that contain vitamin K can affect how well warfarin (Coumadin®) works. Vitamin K is found in green leafy vegetables and some oils, such as canola and soybean oils. It's best to eat a well-balanced, healthy diet.
  • Discuss with your doctor what amount of alcohol is safe for you to drink if you're taking medicine.

Medicines used to treat PE can thin your blood too much. This can cause bleeding in the digestive system or the brain. If you have signs or symptoms of bleeding in the digestive system or the brain, get treatment at once.

Signs and symptoms of bleeding in the digestive system include:

  • Bright red vomit or vomit that looks like coffee grounds
  • Bright red blood in your stool or black, tarry stools
  • Pain in your abdomen

Signs and symptoms of bleeding in the brain include:

  • Severe pain in your head
  • Sudden changes in your vision
  • Sudden loss of movement in your legs or arms
  • Memory loss or confusion

Excessive bleeding from a fall or injury also may mean that your PE medicines have thinned your blood too much.

Once you've had PE (with or without deep vein thrombosis (DVT)), you're at higher risk of having the condition again. During treatment and after, continue to take steps to prevent DVT.

Check your legs for any signs or symptoms of DVT, such as swollen areas, pain or tenderness, increased warmth in swollen or painful areas, or red or discolored skin.

If you think that you have DVT or are having symptoms of PE, contact your doctor right away.