Quick answer
What Is Pulmonary Embolism?
Pulmonary embolism is a blockage in a lung artery, usually caused by a blood clot that has broken off from a leg vein. It is an emergency: sudden shortness of breath, chest pain when breathing in, or fainting needs immediate care in the emergency room.
Sources01 / Understanding the condition
About Pulmonary Embolism
Pulmonary embolism is a blockage in a pulmonary artery, the vessel that carries blood from the right side of the heart to the lungs to pick up oxygen. In most cases, the blockage comes from a blood clot that forms in a deep vein of the leg or pelvis, then breaks off and is carried by the bloodstream through the heart. The blockage can also come from fat, air, or amniotic fluid, but this is much rarer. Because they come from the same process, doctors group pulmonary embolism and deep vein thrombosis together as venous thromboembolism. Clots in the legs are covered on the Deep Vein Thrombosis page.
What Happens to the Lungs and Heart
The part of the lung beyond the blockage receives less blood, so the oxygen level in the blood can drop. The right side of the heart has to pump harder to push blood through the blocked vessels. A small clot may cause mild symptoms, while a large clot can overwhelm the right ventricle, make blood pressure drop, and cause fainting. If part of the lung tissue does not get enough blood flow, chest pain when breathing in and coughing up blood can occur.
Risk Level Guides Treatment
The 2019 ESC guidelines classify pulmonary embolism by risk. High risk means blood pressure drops or shock occurs, so the clot needs to be broken down right away. Intermediate risk means blood pressure is still normal, but the right side of the heart looks strained or markers of heart damage are raised; these patients are closely monitored because their condition can worsen. Low risk means a stable condition without strain on the right side of the heart, and some patients can go home early with tablets.
Treatment and Recovery
Anticoagulant medicines (blood thinners) are started as soon as possible, even before the diagnosis is confirmed if the doctor strongly suspects it, and are continued for at least three months. Clot-dissolving medicines, catheter procedures, or surgery are reserved for severe cases. Many people recover well, but some still feel short of breath or tire easily after several months. That is why a follow-up visit about three to six months after a pulmonary embolism is recommended to assess any remaining symptoms and decide how long treatment should last. Blockages that persist are covered on the Chronic Thromboembolic Pulmonary Hypertension page.
02 / Understanding the condition
Symptoms to Recognize.
Common Symptoms
- Shortness of breath that comes on suddenly or worsens over a few days
- Sharp chest pain that gets worse when breathing in or coughing
- A pounding heart or a fast pulse
- Cough, sometimes with blood-streaked phlegm
- Dizziness, light-headedness, or fainting
- Swelling and pain in one leg, a sign of a clot in a leg vein
- Cold sweats and anxiety without a clear cause
Symptoms in Older Adults
In older adults, pulmonary embolism may appear without typical chest pain, so it is easily mistaken for tiredness or another lung disease.
- New or worsening shortness of breath without a clear cause
- Sudden fainting or falling
- Confusion or weakness that comes on suddenly
- Fast breathing and a fast pulse at rest
Symptoms in Adult Women
The risk of clots rises during pregnancy and until about six weeks after giving birth. Mild breathlessness is common in pregnancy, but sudden shortness of breath needs to be checked.
- Shortness of breath that comes on suddenly during pregnancy or after giving birth
- Chest pain when breathing in during pregnancy or the postpartum period
- Swelling and pain in one leg during pregnancy or after a cesarean section
- A pounding heart with dizziness in the weeks after giving birth
03 / Understanding the condition
What Causes This Condition?
- A blood clot that breaks off from a deep vein of the leg or pelvis, covered on the Deep Vein Thrombosis page
- A clot in an arm vein or a large vein in the chest, often linked to a catheter or device placed inside the vein
- Fat droplets that enter the bloodstream after a fracture of a long bone, such as the thigh bone
- Air bubbles that enter a blood vessel, for example during a medical procedure or diving
- Amniotic fluid that enters the bloodstream during childbirth; this is very rare
- In some people, a clot appears without a clear trigger and needs to be investigated by a doctor
04 / Understanding the condition
Who Is at Higher Risk?
Medical
Major surgery, hospital stays, leg fractures, cancer and chemotherapy, heart failure, severe infections including COVID-19, antiphospholipid syndrome, and a previous deep vein thrombosis or pulmonary embolism.
Lifestyle
Sitting still for long periods, for example on trips longer than four hours, low physical activity, excess body weight, and smoking.
Genetic
Inherited blood clotting disorders, such as factor V Leiden, a prothrombin gene mutation, or a deficiency of protein C, protein S, or antithrombin, as well as a history of blood clots in close family members.
Age
The risk rises with age, especially in older adults who also have other illnesses, surgery, or reduced mobility.
Other
Pregnancy until about six weeks after giving birth, birth control pills or hormone therapy containing estrogen, and catheters or devices placed in large veins.
Groups at Higher Risk
- Surgical and Hospitalized Patients: Major surgery, especially hip and knee surgery, and bed rest slow blood flow in the veins. Your doctor assesses the need for medicine or devices to prevent clots during and after your hospital stay.
- People with Clots in a Leg Vein: Clots in the thigh and pelvic veins can break off and travel to the lungs, especially before treatment begins. Swelling and pain in one leg should be checked the same day.
- People with Cancer: Cancer and some of its treatments make the blood clot more easily. Pulmonary embolism is sometimes found on cancer follow-up CT scans even without symptoms.
- Pregnant and Postpartum Women: The risk of clots rises during pregnancy until about six weeks after giving birth, especially after a cesarean section.
- Older Adults: The risk of clots rises with age, while symptoms are often vague, for example only weakness, confusion, or fainting.
05 / Understanding the condition
How Is It Diagnosed?
Symptoms of pulmonary embolism resemble those of a heart attack, pneumonia, or a panic attack, so doctors use a step-by-step testing pathway. The first step is to check whether blood pressure is stable. If blood pressure is very low, bedside echocardiography can show strain on the right side of the heart and help decide on urgent treatment, and CT pulmonary angiography is done as soon as the patient's condition allows.
In stable patients, the doctor estimates the clinical probability with the Wells or Geneva score. If the probability is low or intermediate, a D-dimer test is done; a normal result can rule out pulmonary embolism. If the probability is high or the D-dimer is raised, CT pulmonary angiography becomes the main test to see the clot directly. A ventilation-perfusion scan is an option during pregnancy, with kidney problems, or with a contrast allergy. Once the diagnosis is confirmed, the doctor assesses the risk level from the size of the right ventricle on echocardiography or CT, troponin and NT-proBNP tests, and clinical scores, because the results determine where you are treated and which treatment you receive. In pregnancy, the diagnostic pathway is adjusted to keep radiation exposure as low as possible.
Physical Examination
Checking blood pressure, pulse, oxygen level, and signs of a clot in the legs, then estimating the clinical probability of pulmonary embolism with the Wells or Geneva score.
D-Dimer Test
When the clinical probability is low or intermediate, a normal result can rule out pulmonary embolism. The cutoff is adjusted for age above 50 years; a high result needs follow-up imaging.
CT pulmonary angiography: a CT scan of the chest with contrast dye given through an IV to see clots in the lung arteries directly; the main test for most patients.
Ventilation-Perfusion Scan
An option without iodine contrast, for example during pregnancy, with kidney problems, or with a contrast allergy. Also used to look for leftover blockages if shortness of breath persists.
Echocardiography
Assesses the size of and strain on the right ventricle. In patients with very low blood pressure, it can be done at the bedside before CT.
Cardiac Biomarkers
Troponin and NT-proBNP help assess the strain on the right side of the heart and determine the risk level of the pulmonary embolism.
Duplex Ultrasound
Looks for clots in the leg veins. If one is found in a patient with symptoms of pulmonary embolism, this supports the diagnosis, including during pregnancy.
06 / Understanding the condition
Treatment Options.
Treatment is decided by a doctor after an assessment. The categories below can help you follow the conversation with your doctor.
Anticoagulant Medicines
Heparin injections or direct oral anticoagulant tablets, sometimes warfarin, for at least three months. The type and duration are decided by your doctor. Covered on the Anticoagulation Therapy and Stroke Prevention page.
Systemic Thrombolysis
Clot-dissolving medicine given by infusion for high-risk pulmonary embolism with low blood pressure. It is not used routinely at intermediate risk, unless the condition gets worse.
Catheter Procedures
Removing or dissolving the clot directly in the lung artery through a catheter, when clot-dissolving medicine cannot be given or has not worked. Covered on the Thrombectomy page.
Surgical Embolectomy
Surgery to remove the clot from the lung artery in certain severe cases, for example when other procedures are not possible.
Oxygen and Circulatory Support
Extra oxygen, careful fluid management, medicines to support blood pressure, and, in very severe cases, a temporary heart-lung support machine.
Vena Cava Filter
A filter in the large vein of the abdomen, used only when anticoagulants cannot be given, and removed again when possible. Covered on the Vena Cava Filter Placement page.
Early Home Treatment for Low-Risk Patients
Selected low-risk patients can go home sooner with tablets, if their home situation is supportive and follow-up visits can be kept regularly.
07 / Understanding the condition
Complications to Watch For.
Acute Right Heart Failure
The right ventricle cannot pump against a large blockage, so blood pressure drops. This requires intensive care and treatment to break down the clot.
Cardiac Arrest
In a very extensive pulmonary embolism, the heart can stop beating. Basic life support and clot-dissolving medicines are part of emergency care.
Pulmonary Infarction
A small area of lung tissue is damaged by a lack of blood flow, causing pain when breathing in and coughing up blood. It usually improves with treatment.
Recurrent Pulmonary Embolism
Clots can come back, especially if medicine is stopped too early or the trigger persists. The length of treatment is decided by the doctor for each person.
Chronic Thromboembolic Pulmonary Hypertension
In a small number of people, leftover clots block the lung arteries over the long term and raise the pressure in the lungs. Covered on the Chronic Thromboembolic Pulmonary Hypertension page.
Persistent Shortness of Breath and Fatigue
Some people still feel short of breath or tire easily for months after a pulmonary embolism. A follow-up visit at three to six months helps find the cause and plan exercise.
Treatment-Related Bleeding
Blood thinners and clot-dissolving medicines raise the risk of bleeding. Your doctor weighs the benefits and risks, and you need to report any sign of bleeding.
08 / Understanding the condition
What Can You Do?
- Move and walk as soon as possible after surgery or illness, as directed by your care team.
- If you are going to have major surgery or a hospital stay, ask your doctor whether you need medicine or a device to prevent clots.
- On trips longer than four hours, stand up and walk regularly and move your ankles.
- Have swelling and pain in one leg checked the same day, so a clot can be treated before it breaks off and travels to the lungs.
- If you are being treated for a clot, take your anticoagulant on schedule and do not stop it on your own.
- Maintain a healthy weight and quit smoking.
- Discuss your clot risk with your doctor before using birth control pills or hormone therapy, especially if you have had a clot before.
09 / Understanding the condition
When Should You See a Doctor?
Pulmonary embolism is an emergency. Go to the emergency room right away or call emergency services if you develop sudden shortness of breath, chest pain when breathing in, coughing up blood, or fainting, especially if you have recently had surgery, stayed in the hospital, taken a long trip, are pregnant, or have recently given birth. Do not drive yourself to the hospital.
- Sudden shortness of breath or chest pain: go straight to the emergency room
- Swelling and pain in one leg: get checked the same day
- Shortness of breath or tiring easily that persists three months after a pulmonary embolism
- Signs of bleeding while taking anticoagulants, such as black stools, reddish urine, or repeated nosebleeds
- Plans for surgery, pregnancy, or a long trip after having had a pulmonary embolism
10 / Common questions
Questions You May Have.
Frequently asked questions about pulmonary embolism.
Can you fully recover from a pulmonary embolism?
Many people recover well after treatment. Blood thinners keep the clot from growing, while the body slowly breaks down the clot over several weeks to months. Some people still feel short of breath or tire easily after a few months, and a small number develop a lasting blockage that raises the pressure in the lungs. That is why doctors recommend a follow-up visit about three to six months after a pulmonary embolism to assess symptoms and, if needed, recheck the lungs and heart.
How long do I need to take blood thinners?
Usually for at least three months. If the pulmonary embolism was triggered by a clear temporary cause, such as major surgery or a fracture, the medicine can often be stopped after that period. If it occurred without a clear trigger, has come back, or has a persistent trigger such as cancer, your doctor may recommend longer treatment after weighing the risk of bleeding. Do not stop or switch your medicine on your own, and tell other doctors or your dentist that you take an anticoagulant.
What is the difference between a pulmonary embolism and a heart attack?
A heart attack occurs when a coronary artery supplying blood to the heart muscle is blocked, while a pulmonary embolism occurs when a lung artery is blocked by a clot. Both can cause chest pain, shortness of breath, and fainting, so they are hard to tell apart from symptoms alone. Pulmonary embolism pain is often sharp and worse when breathing in. Whatever the suspected cause, sudden chest pain and shortness of breath need to be checked in the emergency room immediately. Heart attacks are covered on the Myocardial Infarction / Heart Attack page.
Why am I still short of breath a few weeks after a pulmonary embolism?
Shortness of breath and tiring easily usually ease gradually over several weeks to months, as the clot breaks down and your physical condition recovers. However, shortness of breath that persists or worsens after three months should be checked. The cause may be a leftover blockage in the lung arteries, reduced fitness, or another illness such as a heart problem. Your doctor may perform echocardiography and a ventilation-perfusion scan to look for leftover blockages. Gradual physical exercise as advised by your doctor helps recovery.
Are tests for pulmonary embolism safe during pregnancy?
Testing is still needed and can be done safely, because an unrecognized pulmonary embolism can endanger you and your baby. Doctors use a pathway adapted for pregnancy, for example a leg ultrasound first if you have leg symptoms. If lung imaging is needed, CT pulmonary angiography or a ventilation-perfusion scan gives the baby a low dose of radiation. During pregnancy, the anticoagulant used is generally heparin injections, because heparin does not cross the placenta.
When can I return to my usual activities and travel?
Light activity such as walking can usually start soon after your condition is stable and you are taking blood thinners regularly. Increase your activity gradually according to your ability and your doctor's advice. For long trips or flights, ask your doctor first, especially in the first few weeks. During the trip, stand up and walk regularly, move your ankles, and drink enough fluids. Seek help right away if shortness of breath or chest pain comes back.
Sources and Medical Review
Translated from the Indonesian edition medically reviewed by dr. Santi R. Dewayanti, Sp.P.
Sources as cited in the Indonesian edition.
- Konstantinides SV, Meyer G, Becattini C, Bueno H, Geersing GJ, Harjola VP, et al. 2019 ESC Guidelines for the diagnosis and management of acute pulmonary embolism developed in collaboration with the European Respiratory Society (ERS). Eur Heart J. 2020;41(4):543-603.
- Creager MA, Barnes GD, Giri J, Mukherjee D, Jones WS, Burnett AE, et al. 2026 AHA/ACC/ACCP/ACEP/CHEST/SCAI/SHM/SIR/SVM/SVN Guideline for the Evaluation and Management of Acute Pulmonary Embolism in Adults. J Am Coll Cardiol. 2026;87(13):1626-710.
- Lim W, Le Gal G, Bates SM, Righini M, Haramati LB, Lang E, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: diagnosis of venous thromboembolism. Blood Adv. 2018;2(22):3226-56.
- Ortel TL, Neumann I, Ageno W, Beyth R, Clark NP, Cuker A, et al. American Society of Hematology 2020 guidelines for management of venous thromboembolism: treatment of deep vein thrombosis and pulmonary embolism. Blood Adv. 2020;4(19):4693-738.
- Klok FA, Ageno W, Ay C, Bäck M, Barco S, Bertoletti L, et al. Optimal follow-up after acute pulmonary embolism: a position paper of the European Society of Cardiology Working Group on Pulmonary Circulation and Right Ventricular Function, in collaboration with the European Society of Cardiology Working Group on Atherosclerosis and Vascular Biology, endorsed by the European Respiratory Society. Eur Heart J. 2022;43(3):183-9.
- van der Pol LM, Tromeur C, Bistervels IM, Ni Ainle F, van Bemmel T, Bertoletti L, et al. Pregnancy-Adapted YEARS Algorithm for Diagnosis of Suspected Pulmonary Embolism. N Engl J Med. 2019;380(12):1139-49.
- Kahn SR, de Wit K. Pulmonary Embolism. N Engl J Med. 2022;387(1):45-57.
Doctors Who Treat This Condition
dr. Santi R. Dewayanti, Sp.P
Pulmonology
Clinical focusLung and Respiratory Disease · Asthma and COPD
View Profile
dr. Suko Adiarto, Sp.JP(K), Ph.D.
Interventional Cardiology
Vascular Diagnostic and Therapeutic Center +1 center
Clinical focusCoronary Intervention · Peripheral Vascular Intervention
View Profile
dr. Sri Diniharini, Sp.JP(K)
Echocardiography & Cardiovascular Imaging
Cardiovascular Diagnostic Center +1 center
Clinical focusAdvanced Echocardiography · Transesophageal Echocardiography
View Profile