What is pulmonary embolism?

Pulmonary embolism is the sudden blockage of an artery in the lung. Blood clots in the deep veins of the leg or pelvis (deep vein thrombosis, or DVT) are the most common cause. These blood clots can travel to the lungs.

Pulmonary embolism can be very serious. Because you have had one pulmonary embolism, you are at greater risk for having another one. But you can take steps to prevent another pulmonary embolism.

You will probably take a prescription blood-thinning medicine to prevent blood clots. A blood thinner can stop a blood clot from growing larger and prevent new clots from forming.

Symptoms of pulmonary embolism usually begin all of a sudden. Reduced blood flow to one or both lungs can cause shortness of breath and a rapid heart rate. Inflammation of the tissue that covers the lungs and chest wall (pleura) can cause sharp chest pain.

A blood clot reduces the blood flow and may cause damage to lung tissue. The blood clot might dissolve on its own. If it does, it may not cause any major problems. But without treatment, new clots can form and cause another pulmonary embolism. If pulmonary embolism is diagnosed right away, treatment with anticoagulant medicines may prevent new blood clots from forming.

If a blood clot blocks the artery in the lung, blood flow may be completely stopped, causing sudden death. Doctors will consider aggressive steps when they are treating a large, dangerous pulmonary embolism.

The most common symptoms of pulmonary embolism are sudden shortness of breath; sudden, sharp chest pain that may get worse when you cough or take a deep breath; and a cough. The cough may bring up blood or pink and foamy mucus.

Doctors usually treat pulmonary embolism with medicines called anticoagulants. They are often called blood thinners, but they don't really thin the blood. They help prevent new clots and keep existing clots from growing.

Most people take a blood thinner for a few months. People at high risk for blood clots may take it for the rest of their lives.

If symptoms are severe and life-threatening, "clot-busting" drugs called thrombolytics may be used. These medicines can dissolve clots quickly, but they increase the risk of serious bleeding. Another option is surgery or a less invasive procedure to remove the clot (embolectomy).

Some people may have a filter put into the large vein (vena cava) that carries blood from the lower body to the heart. A vena cava filter may help keep blood clots from reaching the lungs. This filter might be used if you can't take an anticoagulant.

Taking blood thinners reduces your risk of pulmonary embolism. You can also do things that help prevent blood clots in your legs. After an illness or surgery, you can try to get up and out of bed often. You might wear compression stockings. You may try leg exercises that can help blood flow.

Pulmonary embolism can be hard to diagnose. That's because the symptoms are like those of other problems, like a heart attack. A doctor will do a physical exam. You might have tests to look for blood clots or rule out other causes of your symptoms. Tests may include blood tests and a CT angiogram.

Medicines called anticoagulants are used to treat pulmonary embolism. Anticoagulants are also called blood thinners. They can help prevent new blood clots and keep existing clots from growing.

You'll likely take an anticoagulant for at least 3 months. You may take it longer. If your risk for another pulmonary embolism stays high, you might take it for the rest of your life.

Different types of anticoagulants are used. Talk with your doctor about which medicine is right for you.

If you are in the hospital, you might be given an anticoagulant as a pill, a shot, or in a vein through an I.V. After you go home, you might give yourself shots for a few days. For the long term, you'll likely take a pill.

Clot-dissolving (thrombolytic) medicines aren't often used to treat pulmonary embolism. They can quickly dissolve a blood clot. But they also greatly increase the risk of serious bleeding.

• Take your medicines exactly as prescribed. Call your doctor if you think you are having a problem with your medicine. You will get more details on the specific medicines your doctor prescribes.
• If you are taking a blood thinner, be sure you get instructions about how to take your medicine safely. Blood thinners can cause serious bleeding problems.
• Try to walk several times a day. Walking helps keep blood moving in your legs. Before doing other types of exercise, ask your doctor what type and level of exercise is safe for you.
• Take steps to help prevent blood clots in your legs. For example:
  • Exercise your lower leg muscles if you sit for long periods of time. Pump your feet up and down by pulling your toes up toward your knees then pointing them down. Repeat.
  • After an illness or surgery, try to get up and out of bed often. If you can't get out of bed, flex your feet every hour to keep the blood moving through your legs.
  • Take plenty of breaks when you travel. On long car trips, stop the car and walk around every hour or so. On the bus, plane, or train, get out of your seat and walk up and down the aisle every hour, if you can.
  • Wear compression stockings if your doctor recommends them.
  • Check with your doctor about whether you should use hormonal forms of birth control or hormone therapy. These may increase your risk of blood clots.
• Have a healthy lifestyle. This includes being active, staying at a healthy weight, and not smoking.
• Get vaccinated against COVID-19, the flu, and pneumonia.

To improve blood flow, a blood clot can be removed during surgery. Or the clot might be removed with a less invasive procedure that uses a catheter (a thin tube that's guided through a blood vessel). This surgery or procedure is called an embolectomy.

An embolectomy is not common. But it may be done for a few reasons. These include:

• You can't have thrombolytic treatment.
• The clot is so dangerous that you can't wait for medicine to work.
• You've had thrombolytic treatment, but it hasn't worked well enough.

Many things increase your risk for having pulmonary embolism. These include:

• Being older than 40.
• Being overweight.
• Not taking anticoagulant medicine as prescribed.
• Having to stay in bed for more than 3 days (such as in a hospital stay).
• Sitting for a long time, especially when traveling long distances.
• Being pregnant, using hormonal birth control, or using hormone therapy.
• Having a recent surgery or injury that involved the legs, hips, belly, or brain.
• Having certain health problems. These include cancer, blood vessel disease, or an inherited clotting disorder.
• Smoking.

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 aren't deadly, but they can damage the lung. But if the clot is large and stops blood flow to the lung, it can be deadly.

These are some possible problems that can happen from pulmonary embolism:

• Cardiac arrest and sudden death
• Shock
• Abnormal heart rhythm
• Death of part of the lung, called pulmonary infarction
• A buildup of fluid (pleural effusion) between the outside lining of the lungs and the inner lining of the chest cavity
• Paradoxical embolism
• Pulmonary hypertension

Pulmonary embolism is caused by a blocked artery in the lungs. The most common cause of such a blockage is a blood clot that forms in a deep vein in the leg and travels to the lungs. Other things can block an artery, such as tumors or air bubbles. But these are rare.