A pulmonary embolism (PE) is a blockage in one of the arteries in your lungs. Arteries are the blood vessels that carry blood away from the heart to the organs, muscles, and other tissue. Most of the time, the blockage is caused by a blood clot that has traveled from a vein in the legs (deep vein thrombosis or DVT).

A PE can be life-threatening, but it’s a condition that can often be treated successfully. The key is to have a pulmonary embolism diagnosed and treated as soon as possible after symptoms appear.

Pulmonary embolism’s most obvious symptoms include:

  • shortness of breath that gets worse with exertion
  • chest pain or discomfort that worsens when you bend over, cough, or eat
  • passing out

Other potential symptoms include leg swelling, dizziness, a cough that is tinged with bloody sputum (mucus), irregular heartbeat, and excessive sweating.

A PE can also cause serious medical problems or make existing health conditions worse. Read on to learn more about the possible complications of a PE.

If you’ve been diagnosed with a PE, you’ll probably be advised to take anticoagulant medications. These drugs, such as warfarin (Coumadin), help prevent future blood clots that could eventually become pulmonary embolisms.

Scientists are still unclear about the risk of pulmonary embolism recurrence. One study found that among people with PE who stopped taking anticoagulants, more than 22 percent of them had recurrence.

Managing PE with anticoagulants is challenging, because these powerful medications also increase the risk of bleeding problems. It’s important to talk to your doctor about any concerns you have about your treatment.

When your heart suddenly stops beating, the condition is known as cardiac arrest. Cardiac arrest is a problem with your heart’s electrical system. Something causes a disruption with the electrical signals that tell the heart when to beat.

A PE can cause cardiac arrest. And when this happens, the risk of premature death is high. In these emergency situations, administering a drug called a tissue plasminogen activator (tPA) can often be a life-saving procedure. Use of tPA can help get the heart beating in a regular rhythm and break up the clot causing the blockage in the lungs.

Regardless of whether a PE or other cause is to blame for cardiac arrest, this sudden heart problem must be treated as a life-or-death emergency. Rapid treatment is vital to saving the life of anyone who experiences cardiac arrest.

Pleural effusion is also known as “water on the lungs.” It’s a condition in which fluid builds up in between the layers of pleura, which are thin membranes that surround the lungs. Symptoms include shortness of breath, a dry cough, and chest pain.

In most cases, treating the cause of pleural effusion can help improve lung health. Sometimes a procedure to drain fluid from the lungs is necessary.

Pulmonary embolism is the fourth leading cause of pleural effusion, behind heart failure, cirrhosis, and the side effects of open-heart surgery.

One of the most serious complications of a PE is a pulmonary infarction — the death of lung tissue. It occurs when oxygenated blood is blocked from reaching lung tissue and keeping it nourished. Typically, it’s a larger clot that causes this condition. Smaller clots can break up and be absorbed by the body.

Symptoms of pulmonary infarction develop slowly. Tissue death that occurs deep in a lung may not cause any symptoms for a while, since there are no nerve endings in the lung tissue.

When signs of a pulmonary infarction do occur, they can include coughing up blood, sharp chest pain, and fever. Symptoms may gradually disappear after a few days as the dead lung tissue turns to scar tissue. But you should still go to the emergency room if you ever cough up blood.

An arrhythmia is a term to describe any abnormal heart rhythm. An exceedingly fast heartbeat is called tachycardia. A heartbeat that is chaotic and caused by unpredictable quivering of the heart’s upper chambers (atria) is called atrial fibrillation.

There are several other types of arrhythmias, but they all have one thing in common: they’re the result of an abnormality in your heart’s electrical system.

A PE that causes the right side of the heart to work harder can trigger the heart to go into an arrhythmia.

Likewise, a condition such as atrial fibrillation can causes a clot to form in the heart. It could eventually make its way to the lungs and become a PE. When the upper chambers of the heart don’t beat properly, blood can pool in the heart and a clot can form.

It’s critical to treat a PE, because if left untreated, it can lead to pulmonary hypertension. That’s another term for high blood pressure in the arteries in your lungs.

A PE also causes pressure in the right side of your heart to increase. This means your heart’s right side works harder than it should. Over time, the result is heart failure, a weakening of the heart’s pumping ability.

Unusual or abnormal bleeding can occur after you’ve been taking anticoagulant medications. These drugs are strong enough to keep blood from clotting too quickly. However, in some people anticoagulant therapy can cause bleeding problems.

Anticoagulants delay the time it takes for clotting to begin when there’s an external wound or other irritation of tissue inside the body.

Because people who’ve been diagnosed with a PE are usually put on anticoagulant therapy, it’s important to monitor your anticoagulant use closely.

The goal of an embolectomy is to remove a blood clot with a device. One type of embolectomy involves the use of a catheter. A thin, flexible device is inserted into a blood vessel and then guided to the location of the PE. A tiny balloon at the end of the catheter can help “capture” the clot and remove it completely.

This procedure can be effective, but it’s not used very often. There is a risk that the catheter or balloon could injure a major vessel and cause a life-threatening bleeding event.

Being pregnant raises your risk of developing DVT. This is because changes in your hormones can cause your blood to clot more easily. Also, the fetus can press on veins in the uterus, restricting blood flow back to the heart.

A blood clot forming in your veins is 10 times more likely in pregnant women compared to women who aren’t pregnant. You also face a higher risk of DVT and a PE if there are complications during your delivery and veins are damaged.

Your risk is also higher if you’ve had a Cesarean birth and are bedridden for an extended period. Any time you’re bedridden following surgery or when dealing with another health issue, it’s important to try to move your legs in order to boost circulation and prevent blood from pooling, which can cause a clot to form.

A pulmonary embolism can either be the cause of health complications or the result of conditions that affect your circulation. Talk with your doctor about your risk factors for PE, which include:

  • high blood pressure
  • smoking
  • inactivity
  • surgery that leads to a lengthy stay in bed

Ask about whether you should take a blood thinner. If you’ve had a clot anywhere in your body, you are at a higher risk for DVT and a PE, so be sure to work with your doctor on preventive steps you can take to lower your odds of future blood clots that could reach your lungs.