A pulmonary embolism (PE) occurs when blood flow to an artery that supplies blood to the lungs has become blocked, typically due to a blood clot. Complications can develop from either the clot or the treatment for the PE.

PE may begin with a blood clot, or thrombus, that forms in another part of the body, such as the leg. The blood clot can travel to the lung through the circulatory system and lodge in an artery.

Symptoms may include breathlessness, chest pain, cough, fainting, rapid breathing, or an irregular heartbeat.

PE can permanently damage the lungs or result in blood oxygen levels so low that other organs become damaged.

If the clot is small, there may be no complications. However, if the clot is large, it can lead to issues with the lungs or heart or an increased risk of sudden death.

This article discusses the complications that can occur as a result of a PE.

Complications of a pulmonary embolism.Share on Pinterest
Photography courtesy of James Heilman, MD/Wikimedia & gilaxia/Getty Images

PE is a type of venous thromboembolism (VTE). A 2015 article notes that the likelihood of recurrence after a person first develops VTE is 5–7% each year.


After a PE diagnosis, a healthcare professional will prescribe anticoagulants, or blood-thinning medications. This helps prevent future blood clots.

However, anticoagulants can lead to side effects, such as excessive bleeding. People should contact a healthcare professional to discuss the best course of treatment for them.

Approximately 5% of individuals with PE develop chronic thromboembolic pulmonary hypertension (CTEPH), or high blood pressure in the arteries of the lungs, as a result.

Scarring of the blood vessels in the lung narrows their passageways, resulting in labored breathing.

If a person develops persistent or progressive shortness of breath between the first 3 months to 2 years after receiving a PE diagnosis, a doctor may investigate further.

The doctor may order:


People may need to undergo a surgical procedure health experts call pulmonary thromboendarterectomy. This is a complex procedure to remove blood clots from the pulmonary arteries.

A person with CTEPH may need to take anticoagulant medication for the rest of their life.

Pulmonary infarction (PI) occurs when a blood clot blocks the peripheral arteries, preventing some of the lung tissue from receiving enough blood and oxygen. The lung tissue then dies.

According to research from 2021, 30% of people with PE show signs of PI.

Individuals may experience:


There is no specific treatment for PI. Healthcare professionals will focus on treating the PE using anticoagulants and supportive care.

PE is one of the most common causes of pleural effusion, which affects 20–55% of people with PE.

Pleural effusion is when there is a buildup of fluid between the tissues that line the lungs and the chest, called the pleura.

Symptoms can include:

  • sharp chest pain
  • shortness of breath
  • cough


Alongside treating the PE, a healthcare professional may perform surgery to drain the fluid. They may also prescribe diuretics.

For 10–15% of individuals with PE, the heart is unable to pump enough oxygen and blood to the brain and other organs in the body. This can cause a drop in blood pressure and slow down a person’s pulse.

A person may experience:

Cardiogenic shock is a life threatening emergency, as it can result in brain injury or organ failure.


The National Heart, Lung, and Blood Institute notes that treatment focuses on protecting the organs from damage and getting the blood flowing properly.

People may require a heart transplant.

A PE can lead to a cardiac arrest, which increases the risk of death by 95%. Healthcare professionals would classify this as a massive PE.

A cardiac arrest is when the heart suddenly stops beating.


Healthcare professionals may administer a drug called tissue plasminogen activator. This will help break up the blood clots.

A person may also require surgery called venoarterial extracorporeal membrane oxygenation, which is a type of cardiopulmonary bypass surgery.

According to a 2019 article, a PE is the third most common cause of death related to the heart. Approximately 45% of those with acute PE will experience right ventricular failure.

The authors note that the right ventricle is designed to deal with a low resistance afterload. Afterload refers to the pressure that the heart works against in order to eject blood from the chambers and into the arteries.

An increase in the afterload can negatively affect the right ventricle’s ability to function, resulting in right heart failure.

Symptoms can include:


A doctor will first assess the severity of the condition.

Treatment may involve:

Treatment for blood clots involves anticoagulants. If the blood becomes too thin, and a cut or abrasion occurs, an individual can bleed too much.

Symptoms can include:


The American College of Cardiology notes that if the bleeding events are minor, a healthcare professional may recommend missing a few doses of the blood-thinning medication.

In more severe cases, however, they may suggest reversal agents, such as andexanet alfa.

Without treatment, 30% of individuals with PE will die. If a person is able to get treatment, this number reduces to 8%.

If a person experiences any symptoms of a PE, they should seek immediate medical attention.

People may have an increased risk of developing a PE if they have been in any of the following situations:

  • They have recently had a surgery, especially joint replacement surgery.
  • They have experienced physical trauma, such as a broken leg.
  • They have taken hormone-based medicine, including oral birth control.
  • They have been pregnant or given birth.
  • They have had cancer or heart or lung disease.
  • They have not moved for a long period, for instance, due to bed rest or a long trip.

Other factors that increase risk include:

  • being over 40 years of age
  • having a family history of blood clots
  • having obesity

To prevent complications from PE, early diagnosis is essential. If any symptoms of PE arise, a person should seek medical attention immediately.

These symptoms include:

Some complications develop due to underlying heart or lung conditions. To prevent PE complications, a person can try the following:

PE can be a serious condition if the blood clot is large or if there are many blood clots.

If any symptoms of PE develop, a person should seek medical attention right away. If a PE has already occurred, and any new symptoms, such as shortness of breath, develop, people should contact a doctor immediately.

If an individual takes blood thinners, and they experience excessive bleeding, a healthcare professional may need to adjust their treatment.

PE is a serious condition that occurs due to a blood clot traveling to an artery in the lung. It may first form in the leg, abdomen, or pelvis and travel to the lung via the circulatory system.

PE may lead to complications. These may include excessive bleeding from treatment with blood thinners, recurring blood clots, pulmonary hypertension, or cardiogenic shock.

Some factors increase the risk of a PE, such as bed rest, long travel, recent trauma, pregnancy or giving birth, and taking hormone-based medication.