Pulmonary Embolism

A pulmonary embolism is a serious medical emergency that occurs when a blood clot blocks an artery in the lungs, cutting off blood flow and oxygen supply. Quick treatment can save lives, but about 33% of people die before they receive diagnosis and treatment.

Table of contents

• What is a pulmonary embolism?
• Symptoms and warning signs
• What causes a pulmonary embolism?
• Risk factors
• How is it diagnosed?
• Treatment options
• Recovery and living with pulmonary embolism
• Preventing blood clots

What is a pulmonary embolism?

A pulmonary embolism (PE) is a blood clot that blocks one of the blood vessels in your lung^[1]. This happens when a clot from another part of your body, usually your leg or arm, travels through your veins to your lung^[2]. The blockage stops blood from flowing properly to your lungs, which lowers oxygen levels in your lungs and increases blood pressure in your pulmonary arteries (the blood vessels that carry blood to your lungs)^[2].

This condition is a medical emergency. Without quick treatment, a pulmonary embolism can cause serious damage to your lungs and heart, and can even be life-threatening^[2]. The good news is that with timely diagnosis and treatment, a PE is seldom fatal^[2].

Pulmonary embolism is one of the most common heart and blood vessel diseases in the world. It ranks third behind heart attack and stroke^[2]. In the United States, about 900,000 people a year experience a PE^[2].

Most pulmonary embolisms result from a blood clot in the leg called a deep vein thrombosis (DVT)^[1]. Together, PE and DVT are known as venous thromboembolism (VTE)^[4].

• Lungs
• Pulmonary arteries
• Deep veins (usually in legs)
• Heart

Symptoms and warning signs

The first signs of pulmonary embolism are usually shortness of breath and chest pains that get worse if you exert yourself or take a deep breath^[2]. If you have these symptoms, get medical attention right away.

Pulmonary embolism symptoms can vary greatly, depending on how much of your lung is involved, the size of the clots, and whether you have underlying heart or lung disease^[1]. Some people have mild symptoms that appear over several days or even weeks, while others get symptoms just minutes or even seconds after a pulmonary embolism happens^[2].

Common symptoms include^[1][2]:

• Sudden shortness of breath, whether you’ve been active or at rest
• Chest pain that often gets worse when you breathe in deeply or cough
• Rapid breathing and fast heartbeat
• Coughing, with or without bloody mucus
• Wheezing
• Pale, clammy, or bluish skin
• Excessive sweating
• Lightheadedness, feeling faint, or passing out
• Feelings of anxiety

You may also have symptoms of a deep vein thrombosis in your leg, such as swelling, pain, redness, and warmth^[1].

Sometimes people with PE don’t have any symptoms until they develop serious complications^[5]. About 33% of people with a pulmonary embolism die before they get a diagnosis and treatment^[2].

What causes a pulmonary embolism?

The cause is usually a blood clot that breaks loose and travels through the bloodstream to the lungs^[5]. The clot is most often a deep vein thrombosis (DVT), which forms in a deep vein in the leg^[5].

Several things can lead to blood clots forming^[2]:

• Blood collecting or “pooling” in a certain part of your body, usually an arm or leg. Blood usually pools after long periods of inactivity, like after surgery, bed rest, or a long flight or car ride
• Injury to a vein, such as from a fracture or surgery, especially in your pelvis, hip, knee, or leg
• Another medical condition, like cardiovascular disease, including congestive heart failure, atrial fibrillation, heart attack, or stroke
• An increase or decrease in your blood’s clotting factors. Elevated clotting factors can occur with some types of cancer or in some people taking hormone replacement therapy or birth control pills

In rare cases, material such as air bubbles, clumps of fat, or parts of a tumor can block the lung artery and cause PE^[5].

Risk factors

Anyone can get a pulmonary embolism, but certain things can raise your risk^[2][5]:

• Having a blood clot in your leg or deep vein thrombosis (DVT)
• Being inactive for long periods of time while traveling by motor vehicle, train, or plane
• Having surgery, especially joint replacement surgery
• Experiencing a serious injury, such as a broken hip or leg bone
• Being on bed rest for an extended period
• Having cancer or undergoing cancer treatment
• Having heart or lung diseases
• Taking hormone-based medicines, such as birth control pills or hormone replacement therapy
• Pregnancy and childbirth (the risk is highest for about six weeks after childbirth)
• Being older, especially after age 40
• Having a family history of blood clots and certain genetic changes that increase your risk
• Being overweight or obese
• Smoking

How is it diagnosed?

It can be difficult to diagnose PE, especially if you have underlying heart or lung disease^[8]. To find out if you have a PE, your healthcare provider will take your medical history, ask about your symptoms and risk factors, do a physical exam, and likely order some tests^[5].

Diagnosis is based on signs and symptoms in combination with test results^[4]. If the risk is low, a blood test known as a D-dimer may rule out the condition^[4]. D-dimer tests measure substances in the blood that may be signs of a blood clot^[6].

Common diagnostic tests include^[5][6][8]:

• CT pulmonary angiography (CTPA): This test takes pictures of your blood vessels and looks for blood clots in the lungs. It is the main test to diagnose pulmonary embolism
• Chest X-ray: Although X-rays can’t diagnose a pulmonary embolism and may even appear normal when a PE exists, they can rule out other conditions with similar symptoms
• Ultrasound: A test called duplex ultrasonography uses sound waves to scan veins in your leg to check for deep vein blood clots
• Ventilation-perfusion scan (V-Q scan): This test looks at blood flow and air flow in your lungs
• Blood tests: These measure oxygen and carbon dioxide levels in your blood and check for clotting factors
• Electrocardiogram (EKG): This test measures your heart’s electrical activity

Treatment options

If you have PE, you need medical treatment right away. The goal of treatment is to break up clots and help keep other clots from forming^[5]. Treatment options depend on how many clots you have, the severity of the clot, the location of the clot, and your overall health^[13].

Medicines

Anticoagulants, or blood thinners, are the most common treatment for pulmonary embolism^[5][13]. These medicines keep blood clots from getting larger and stop new clots from forming. You might get them as an injection, a pill, or through an I.V. (intravenous). Blood thinners can cause bleeding, especially if you are taking other medicines that also thin your blood, such as aspirin.

Thrombolytics, also called clot busters, are medicines that dissolve blood clots^[5][13]. You may get them if you have large clots that cause severe symptoms or other serious complications. Thrombolytics can cause sudden bleeding, so they are used only if your PE is serious and may be life-threatening.

Procedures

Some patients may need minimally invasive procedures to treat their pulmonary embolism^[13]:

• Catheter-assisted thrombus removal: A flexible tube is inserted into a blood vessel to reach the blood clot in your lung. A tool in the tube can break up the clot or deliver medicine through the tube^[5]
• Catheter-directed thrombolysis: This delivers clot-busting medication directly to the clot^[13]
• Mechanical thrombectomy: A catheter is used to physically remove the clot^[13]

A vena cava filter may be used in some people who cannot take blood thinners^[5]. Your healthcare provider inserts a filter inside a large vein called the vena cava. The filter catches blood clots before they travel to the lungs, but it does not stop new blood clots from forming.

In severe cases where a pulmonary embolism clot does not dissolve and becomes life-threatening, surgery may be needed^[13]. A surgeon may use a catheter or may need to operate on your chest to access the clot quickly.

Recovery and living with pulmonary embolism

Recovery from a pulmonary embolism can take several weeks or months^[15]. Most people can walk and do light housework right away after a pulmonary embolism, but you may get tired easily or feel short of breath^[15].

You will probably take prescription blood-thinning medicine to prevent blood clots^[17]. You can expect to take blood thinners for at least 3 months and possibly much longer. Some people need to take them for life^[15].

When taking blood thinners, you may need to change what you eat and drink^[15]. For example, foods rich in vitamin K, which helps your body form blood clots, may change the way blood thinners work. You should try to eat the same amount of leafy green vegetables, fish, liver, and some kinds of vegetable oils that you have been eating. You also should talk to your doctor about any other prescription or over-the-counter medicines you take, as some common medicines can affect how blood thinners work.

Your doctor will likely give you specific exercises to do for several weeks or months to help boost your strength and breathing^[15]. Try to walk several times a day, as walking helps keep blood moving in your legs^[17]. Before doing other types of exercise, ask your doctor what type and level of exercise is safe for you.

Some people may benefit from a pulmonary rehabilitation program, which is an outpatient program that focuses on education, exercise, and one-on-one meetings with healthcare providers to help strengthen your recovery process^[18].

This kind of serious, painful experience can leave you feeling sad or scared^[15]. If you feel anxious or depressed, talk with your doctor about a referral to a counselor or support groups in your area.

Because you have had one pulmonary embolism, you are at greater risk for having another one^[17]. Watch closely for changes in your health. Call your doctor right away if you notice any signs of a new blood clot, such as swelling, pain, tenderness, warmth, or redness in your leg^[17].

Preventing blood clots

There are several steps you can take to prevent blood clots and reduce your risk of another pulmonary embolism^[17][19]:

• Stay active: Try to walk several times a day. Walking helps keep blood moving in your legs
• Exercise your lower leg muscles if you sit for long periods: Pump your feet up and down by pulling your toes up toward your knees then pointing them down
• Take breaks on long trips: On long car trips, stop and walk around every hour or so. On a bus, plane, or train, get out of your seat and walk up and down the aisle every hour if you can
• After 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
• Wear compression stockings if your doctor recommends them: These special socks get tighter as they go down toward your ankle, which helps your leg muscles move blood up your leg
• Maintain a healthy lifestyle: Be active, stay at a healthy weight, and don’t smoke
• Stay hydrated: Drink plenty of water to avoid getting dehydrated
• Talk to your doctor about hormone-based medicines: Some forms of birth control or hormone therapy may increase your risk of blood clots

Get vaccinated against COVID-19, influenza (flu), and pneumonia^[17].

If you have any of these symptoms, go to your nearest emergency department or call for an ambulance^[17]:

• Shortness of breath or difficulty breathing
• Chest pain
• Heart palpitations
• Fast breathing and heart rate
• Coughing up blood
• Fainting or lightheadedness