What is Pulmonary embolism (PE) ?
Pulmonary embolism is a blockage in one of the arteries in your lungs In most cases pulmonary embolism is caused by clots that travel to the lungs from deep veins in your legs or rarely from other parts of the body (deep vein thrombosis)
Because the clots block blood flow to the lungs pulmonary embolism can be life-threatening However prompt treatment greatly reduces the risk of death Taking measures to prevent blood clots in your legs will help protect you against pulmonary embolism
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Explanation of medical terms and concepts
Pulmonary embolism (PE)
Symptoms Pulmonary embolism (PE)
Pulmonary embolism symptoms can vary considerably depending on how much of the lung is involved the size of a clot and whether there are underlying lung or heart disease
Common signs and symptoms include:
- Shortness of breath.This symptom shows up suddenly and gets worse with exertion
- Chest pain.You may feel like you are having a heart attack The pain can be sharp and felt when you breathe in deeply Often it prevents you from being able to take a deep breath It can also be felt when you cough bend or stoop
- Cough.The cough may produce bloody or blood-streaked sputum
Other symptoms that might accompany pulmonary embolism include:
- Rapid or irregular heartbeat
- Lightheadedness or dizziness
- Excessive sweating
- Fever
- Leg pain or swelling in the calf is usually caused by a deep vein thrombosis
- Clammy or discolored skin (cyanosis)
When to see a doctor
Pulmonary embolism can be life-threatening Seek immediate medical treatment if you experience unexplained shortness of breath chest pain or a cough that produces bloody sputum
Causes Pulmonary embolism (PE)
Pulmonary embolism occurs when a clot of material (usually blood) gets wedged in an artery in your lungs These clots most commonly come from the deep veins of your legs (a condition known as deep vein thrombosis or DVT)
In many cases multiple clots are involved in pulmonary embolism The portions of lung served by each blocked artery are robbed of blood and may die This is known as pulmonary infarction This makes it more difficult for your lungs to provide oxygen to the rest of your body
Occasionally blockages of the blood vessels are caused by substances other than blood clots such as:
- Bone marrow is the soft fatty tissue inside bones
- Part of a tumor
- Air bubbles
Risk factors Pulmonary embolism (PE)
Certain factors can increase your risk of developing blood clots and pulmonary embolism
Medical conditions and treatments
If you or any of your family members have had venous blood clots in the past you are at higher risk for developing this disorder
Some medical conditions and treatments put you at risk such as:
- Heart disease.Cardiovascular diseases that make clot formation more likely are specifically heart failure congestive heart failure and hypertension
- Cancer. Certain cancers especially brain ovary pancreas colon stomach and lung cancers and cancers that have spread can increase the risk of blood clots Women with a personal or family history of breast cancer who are taking tamoxifen or raloxifene are at an increased risk of developing blood clots while also being at an increased risk of chemotherapy further increasing their risk raloxifene is associated with higher risk of blood clots
- Surgery.A lot of surgeries are the leading cause of blood clots for this reason it is recommended to take medication before and after these surgeries to prevent blood clots
- Disorders that affect clotting.Some inherited disorders affect blood clotting and other medical disorders such as kidney disease can increase your risk of blood clotting
- Coronavirus disease 2019 (COVID-19).People who have severe symptoms of COVID-19 have an increased risk of pulmonary embolism
Prolonged immobility
Blood clots are likely to form during periods of inactivity such as:
- Bed rest. Being confined to bed for an extended period after surgery a heart attack leg fracture trauma or any serious illness makes you more susceptible to blood clots When the lower extremities are horizontal for long periods the flow of venous blood slows and blood can pool in the legs sometimes resulting in deep vein thrombosis Blood clots are dangerous because they can travel to other parts of your body including your lungs and brain causing serious problems In blood clots
- Long trips.Sitting in cramped positions during long car or plane rides can contribute to the formation of blood clots in the legs
Other risk factors
- Smoking.Tobacco use especially cigarette smoking and chewing tobacco predispose some people to blood clot formation This is because tobacco contains a chemical known as nicotine that causes the blood vessels to constrict (narrow) which increases pressure in the veins and arteries The increase in pressure can cause them to leak leading to an abnormally rapid loss of blood from small vessels that feed the heart muscle
- Being overweight.Excess weight increases the risk of blood clots including those in people with other risk factors
- Supplemental estrogen.Estrogen in birth control pills and hormone replacement therapy can increase clotting factors in your blood especially if you smoke or are overweight
- Pregnancy.Falls and accidents can lead to chronic blood pressure problems The weight of the baby pressing on veins in the pelvis can slow blood return from the legs Clots are more likely to form when blood slows or pools
Complications
Pulmonary embolism is a life-threatening condition in about one-third of people with undiagnosed and untreated pulmonary embolism When the condition is diagnosed and treated promptly however that number drops dramatically
Pulmonary embolism can also cause pulmonary hypertension When you have obstructions in the arteries inside your lungs your heart has to work harder to push blood through those vessels High blood pressure and heart disease can lead to death
In rare cases small emboli occur frequently and develop over time resulting in chronic pulmonary hypertension also known as chronic thromboembolic pulmonary hypertension
Prevention Pulmonary embolism (PE)
To prevent clots in the deep veins in your legs (deep vein thrombosis) it is recommended to first stop smoking The reason for this recommendation is that there are a high percentage of persons who have not stopped smoking will develop pulmonary embolism which can cause death In addition hospitals are aggressive about preventing blood clots and take measures to do so including:
- Blood thinners (anticoagulants).These medications are sometimes given to people who have a high risk of developing blood clots before and after an operation as well as to people admitted to the hospital with medical conditions such as heart attack stroke or complications of cancer
- Compression stockings.Compression stockings steadily squeeze your legs helping to improve the flow of blood in your veins and leg muscles They are safe simple inexpensive and a good way to keep blood from stagnating during and after surgery
- Leg elevation.Elevating your legs at night and whenever possible can be very effective Raise the bottom of the bed by 4 to 6 inches (10 to 15 cm) with blocks or books
- Physical activity.Moving as soon after a surgery as possible can help prevent pulmonary embolism and hasten recovery overall This is one of the main reasons your nurse may push you to get up even on your day of surgery even though it hurts at the site of your surgical incision
- Pneumatic compression.The type of cuffs I use are thigh-high or calf-high which automatically inflate and deflate every few minutes to massage my legs and improve blood flow
Prevention while traveling
The risk of blood clots developing while traveling is low Long haul travel increases the risk of blood clots so if you have risk factors for blood clots and you're concerned about traveling talk with your doctor
Your doctor might suggest the following to help prevent blood clots during travel:
- Drink plenty of fluids.Water is the best liquid for preventing dehydration which can contribute to the development of blood clots and it's better to avoid alcohol which contributes to fluid loss
- Take a break from sitting.Move around the car every hour or so If you’re driving stop every so often and walk around the car a couple of times Do a few deep knee bends
- Fidget in your seat. Flex your ankles every 15 to 30 minutes.
- Wear support stockings.Your doctor may recommend these to help promote circulation and fluid movement in your legs Compression stockings are available in a range of stylish colors and textures There are even devices called stocking butlers to help you put on the stockings
Diagnosis Pulmonary embolism (PE)
Pulmonary embolism can be difficult to diagnose It is often missed by the doctor because people with underlying heart or lung disease are often not aware of their condition For that reason your doctor will likely discuss your medical history and physical exam order one or more of the following tests:
Blood tests
Your doctor may order a blood test for the clot-dissolving substance D dimer High levels of D dimer can indicate an increased likelihood of blood clots although many other factors can also cause high D dimer levels
Blood tests 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
Blood tests may be done to determine if you have an inherited clotting disorder
Chest X-ray
A noninvasive test for pulmonary embolism and other heart and lung conditions can show images of your heart and lungs This test is called a chest X-ray Although X-rays can’t diagnose pulmonary embolism they may not show signs of the disease if it exists
Ultrasound
Duplex ultrasonography (sometimes called duplex scan or compression ultrasonography) uses sound waves to scan the veins in your thigh knee and calf for deep vein blood clots
An ultrasound wand is held over the skin and sound waves are bounced off of blood vessels The reflection of the sound waves creates a moving image on a computer screen The absence of clot means less thrombosis (the formation of clots) in the veins The treatment will probably be started immediately
CT pulmonary angiography
CT scanning uses X-rays to create cross-sectional images of your body This is called a CT pulmonary angiogram It can detect abnormalities such as pulmonary embolism within the arteries in your lungs Sometimes contrast material is given to help doctors see details they might otherwise miss or determine if there's a problem with the lungs The pulmonary arteries are outlined on the CT scan
Ventilation-perfusion scan (V/Q scan)
A V/Q scan is a test that can be performed to determine if you have too much radiation exposure or contrast from a CT scan due to a medical condition In this test a tracer is injected into your arm The tracer maps blood flow (perfusion) and compares it with the airflow to your lungs (ventilation) This test can help determine if you have too much radiation exposure and contrast from a CT scan due to medical conditions To determine whether blood clots are causing symptoms of pulmonary hypertension the doctor may use a test to check for the presence of a protein called fibrinopeptide A
Pulmonary angiogram
This test provides a clear picture of the blood flow in your lungs It is the most accurate way to diagnose pulmonary embolism but because it requires a high degree of skill to administer and has potentially serious risks it's usually performed when other tests fail to provide an accurate diagnosis a definitive diagnosis
In a pulmonary angiogram a flexible tube (catheter) is inserted into a large vein usually in your groin This can be done through an artery in your heart or through a vein at the side of your neck and threaded through the arteries that supply blood to the heart and pass through the lungs Special dye is injected into the catheter and X-rays are taken as the dye travels along these arteries in your lungs The procedure is called “pulmonary ang The lungs are connected to the heart
The dye in some people may cause a temporary change in heart rhythm and the dye may increase risk of kidney damage in people with reduced kidney function
MRI
MRI is a medical imaging technique that uses a magnetic field and computer-generated radio waves to create detailed images of the organs and tissues in your body MRI is usually reserved for pregnant women (to avoid radiation to the fetus) and people whose kidneys may be harmed by dyes used in other medical imaging techniques tests
Treatment Pulmonary embolism (PE)
Treatment of pulmonary embolism aims at keeping the blood clot from getting bigger to prevent more clots from forming and to prevent serious complications or death Prompt treatment is essential to prevent serious complications or death
Medications
Medication may include different types of blood thinners and clot dissolvers
Blood thinners (anticoagulants). Heparin is a frequently used anticoagulant that can be given through the vein or injected under the skin It acts quickly and is often overlapped for several days with an oral anticoagulant such as warfarin which keeps your blood thin Inject a drug such as warfarin to make it work This medication works slowly but it can take days for its action to be effective
Some anticoagulants work more quickly and have fewer interactions with other medications because they are given by mouth However all anticoagulants have side effects and bleeding is the most common
- Clot dissolvers (thrombolytics).Clots usually dissolve on their own but sometimes thrombolytics given through a vein can dissolve clots quickly These clot-busting drugs can cause sudden and severe bleeding so they are usually reserved for life-threatening situations
Surgical and other procedures
- Clot removal.If you have a very large life-threatening clot in your lung your doctor may suggest removing it via a thin flexible tube (catheter) threaded through your blood vessels
- Vein filter. A catheter may also be used to position a filter in the body's main vein (inferior vena cava) in order to keep clots from going to your lungs This procedure is typically reserved for people who cannot take anticoagulants Some filters can be removed when no longer needed
Ongoing care
It's important to continue your treatment for a future deep vein thrombosis or pulmonary embolism as these complications may occur again Also it is important to keep regular appointments with your doctor so you can prevent or treat the complications of previous blood clots
Clinical trials
Explore new studies at Mayo Clinic to test new tests and treatments for this condition
Preparing for your appointment
If you suspect that you might have a pulmonary embolism seek immediate medical attention
What you can do
You may want to make a list which includes:
- Detailed descriptions of your symptoms
- Information about your past medical problems especially recent surgeries or illnesses that kept you almost bedridden for several days
- Details about any recent long car or plane trips
- If you're taking any medications including vitamins and herbal products and any other supplements as well as the dosages of these medications you need to let me know
- Information about medical problems that have been experienced by parents siblings or spouses
- Questions you want to ask the doctor
What to expect from your doctor
During the physical exam you doctor will likely inspect your legs to determine if there is evidence of a deep vein clot These could be painful warm red and tender areas that are swollen The doctor will also listen to your heart and lungs and check your blood pressure
General summary
symptoms What are the symptoms? Chest pain dyspnea and tachypnea
(PE) Pulmonary embolism is a serious condition that occurs when one or more of the deep veins in the lungs (called pulmonary veins) become blocked Blood cannot flow normally through these blocked veins and it will back up into the venous side of the heart It can also travel to other parts of the lung causing tissue damage and even death The risk factors for PE include obesity pregnancy surgery or injury that causes blood clotting cancer and certain medications such as birth control pills or hormone replacement therapy People who have had a previous episode of PE are at an increased risk of having another one
signs and symptoms The main symptom of pulmonary embolism is shortness of breath With a PE the left lower side of your lung will feel tight and heavy which may make breathing very difficult In addition to shortness of breath you may also experience chest pain sharp heartbeats (palpitations) a cough that produces blood-tinged sputum fever or chills and anxiety If you develop any new or unusual symptoms while on vacation or away from home seek medical attention immediately
What can cause pulmonary embolism?
Though there are many factors that contribute to the formation of a pulmonary embolism including trauma surgery cancer and pregnancy According to the American Heart Association risk factors for developing a PE include: Having had a clot previously Being male or older than 60 years of age Blood disorders such as hypofibrinogenemia (low levels of fibrinogen) or factor V Leiden mutation (a genetic variation in which the blood protein Factor V doesn't function properly) These conditions increase one's risk for clots by abating blood clotting mechanisms
Pulmonary embolism (PE) is a serious condition that can occur when a blood clot becomes lodged in one of the major veins in lungs If left untreated PEs may decrease your ability to breathe and lead to death So it's important to know the warning signs so you can seek treatment right away if you experience them
What is the survival rate of a pulmonary embolism?
The survival rate of a pulmonary embolism is quite high Pulmonary emboli are often discovered when patients undergo scanning for problems in other parts of the body such as the heart or a vein in the leg When an embolus is detected treatment begins immediately to prevent further damage to the lungs and other organs and blood vessels
How long before a pulmonary embolism becomes fatal?
Chest pain shortness of breath dizziness and rapid heartbeat are all symptoms of a pulmonary embolism (PE) With proper treatment the condition usually can be treated successfully If not detected early however PE could become fatal within minutes Prompt diagnosis is essential because PE occurs in approximately 600,000 Americans each year That's more than both strokes and tuberculosis combined
Can you fully recover from a pulmonary embolism?
If you are treated with anticoagulants then chances are good that you will fully recover If your PE is identified and treated early before a severe blockage develops there's an excellent chance of full recovery without long-term damage or any lasting symptoms