What is pulmonary embolism?
A pulmonary embolism is a clump of material (usually a blood clot) that gets stuck while moving through your bloodstream and blocks a blood vessel in your lungs.
A pulmonary embolism blocks a blood vessel in your lungs, which makes it hard for blood to pass through your lungs and get oxygen
A small pulmonary embolism may not be dangerous but the bigger the embolism, the more harm it causes
The most common symptom is trouble breathing
A big pulmonary embolism can cause death right away
Doctors treat pulmonary embolism with blood thinners for a few months
If you keep having pulmonary embolisms, you may need to take blood thinners for the rest of your life
What causes pulmonary embolism?
A pulmonary embolism is usually caused by a blood clot. Not all blood clots cause harm. For example, blood clots are needed to stop the bleeding in a cut. However, blood clots can form inside blood vessels when they aren’t needed, as in deep vein thrombosis Deep Vein Thrombosis (DVT) Deep vein thrombosis (DVT) is when a blood clot forms inside a large vein. Usually the vein is deep in your leg, but a clot may form in a vein in your pelvic area or your arm. A blood clot is... read more . Most often, these unnecessary blood clots form in big veins deep inside your legs. These clots can break off and travel to your lungs or your heart.
Certain conditions increase your chance of having a pulmonary embolism including:
Older age (usually over 60)
Previous blood clots
A broken leg or hip
Major surgery within the past 3 months
Taking the hormone estrogen or medicines similar to it
In general, you're more likely to get blood clots in your legs when you can't move your legs much. You might not move much if you break a leg. Also, when you have surgery or a long illness, you may have to lay in bed for awhile. Even taking a long plane flight can be a risk because it can keep you from moving your legs enough.
Sometimes other substances can cause a pulmonary embolism. These include:
Fat released from broken bones or during surgery on bones (orthopedic surgery)
Fluid that surrounds a baby in the womb (amniotic fluid) released into your blood during a difficult delivery
Air bubbles from underwater diving
Foreign material mixed in with illegal drugs that are injected
What are the symptoms of pulmonary embolism?
A small pulmonary embolism might not cause any symptoms. If you do have symptoms, they often include:
Shortness of breath
Light-headedness or fainting
If the pulmonary embolism came from a blood clot in your leg, that leg may be swollen and painful. Sometimes you might not have any symptoms in your leg.
How can doctors tell if I have pulmonary embolism?
Pulmonary embolism can be hard for doctors to recognize. Your doctor will ask about your symptoms and what risk factors you have.
Because the symptoms of pulmonary embolism can be like those of other types of heart and lung disorders, doctors usually start with general tests such as:
Measuring how much oxygen is in your blood using a sensor placed on your fingertip
If your symptoms or test results suggest you might have a pulmonary embolism, your doctor may:
Do a blood test to look for signs of too much blood clotting
Do a CT (computed tomography) scan of your chest after giving you a few ounces of liquid in your vein that makes your blood vessels show up better (CT angiography Variations of CT Computed tomography (CT) is a type of medical imaging that combines a series of x-rays to create cross-sectional, detailed images of internal structures. In computed tomography (CT), which used... read more )
Less often, your doctor may do a lung scan Radionuclide Scanning Radionuclide scanning is a type of medical imaging that produces images by detecting radiation after a radioactive material is administered. During a radionuclide scan, a small amount of a radionuclide... read more . In a lung scan, the doctor injects a small amount of radioactive liquid in your vein. Then the doctor takes pictures of your chest with a camera that detects radiation. The lung scan can show whether blood is flowing to all parts of your lungs.
How do doctors treat pulmonary embolism?
Doctors use different treatments depending on how severe the embolism is.
Be cared for in the hospital
Get blood thinning medicines (anticoagulants) to prevent more clots from forming
The blood thinner may be given by mouth, directly into your vein (IV), or by shots under your skin. When you go home, you'll take a blood thinner for a few months. If you have serious risk factors or have had several pulmonary embolisms, you may need to take the blood thinner for your whole life.
If you have a large, dangerous clot in your lungs that could be fatal, doctors may:
Give clot-busting medicine IV to dissolve the clot
Rarely, try to remove the clot using a special IV catheter or doing surgery
If you can't take blood thinners or you keep having clots despite blood thinners, doctors may:
Put a wire mesh filter in the big vein in your abdomen to keep clots in your legs from getting to the lungs
Inferior Vena Cava Filters: One Way to Prevent Pulmonary Embolism
To prevent pulmonary embolism, doctors usually use medicines that limit blood clotting. However, for some people, doctors may recommend that a filter (formerly called an umbrella) be temporarily or permanently placed in the inferior vena cava. This filter device typically is recommended when medicines can't be used, for example, when a person is also having bleeding. The filter can trap emboli before they reach the heart but allow blood to flow through freely. Emboli that are trapped sometimes dissolve on their own.
How can I prevent pulmonary embolism?
You usually need to take preventive measures if:
You have had pulmonary embolism or blood clots in your legs before
You're having certain types of surgery, particularly orthopedic surgery on your hips or legs
You have cancer or a disorder that makes your blood clot too much
You're going to be in a hospital bed for a long time without being able to get up
Doctors advise different measures depending on your circumstances. They may have you:
Take blood thinners for a little while right after surgery
Take blood thinners for a long time if you have had pulmonary embolism or blood clots before
Wear long, tight stockings (compression stockings) or inflatable boots that squeeze your lower leg muscles off-and-on to keep the blood moving well
Get out of bed and walk around as soon as possible after a surgery
You can help prevent blood clots on airplane flights by:
Doing leg exercises
Moving more—for example, standing, stretching, and walking around at least every 2 hours