Pulmonary Embolism

1 What is Pulmonary Embolism?

Pulmonary embolism is a serious condition where a blood clot blocks an artery in the lungs.

This blood clot often forms in the veins of the leg, which has a more direct pathway to the lungs and can cause a blockage. Rarely, blood clot originated from other parts of the body. The most common cause of blood clot formation in the legs is deep vein thrombosis (DVT).

You can get DVT from sitting or lying down too long. DVT and pulmonary embolism often occur together, and so both are referred to as venous thromboembolism.

Anyone can have a pulmonary embolism, especially those with conditions that cause moderate immobility like cancer or surgery. Pulmonary embolism cuts off blood circulation in the lungs, so it is life-threatening and can quickly cause death if not treated immediately.

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2 Symptoms

Fast recognition of symptoms of pulmonary embolism is important.

Here are the symptoms of pulmonary embolism:

  • Shortness of breath, often occurring suddenly and becomes worse with exertion.
  • Chest pain often described similar to heart attack and does not go away with rest. Chest pain in pulmonary embolism becomes worse when you breathe deeply, cough, bend or stoop, and during exertion. 
  • Cough, sometimes with bloody or blood-tinged sputum

Here are other signs or symptoms of pulmonary embolism:

Since pulmonary embolism is life threatening, do call the doctor immediately.

3 Causes

The most common cause of pulmonary embolism is deep vein thrombosis. It happens because the veins in the leg travel directly to the heart, where it is pumped to the lungs. Therefore, any clots in the leg are very likely to end up in the arteries of the lungs. Substances other than blood clots can also cause pulmonary thrombosis, like fat from the marrow of a broken bone, part of a tumor, or even air bubbles.

The lungs have extensive blood supply due to its role in putting oxygen and removing carbon dioxide from the bloodstream. Blood clots can easily cut off the blood supply to a section or lobe of the lung. The sudden loss of blood supply causes shortness of breath and chest pain.

Most cases of pulmonary embolism involve multiple clots clogging several portions of the lung. In some cases, the loss of blood supply causes the lung tissue to die to result in pulmonary infarction. Areas of non-functioning lung tissue make it harder for your lungs to oxygenate the body.

4 Making a Diagnosis

Pulmonary embolism requires immediate medical care, so it is usually diagnosed in hospitals or emergency centers.

If you suspect that you or someone has a pulmonary embolism, seek medical care immediately.

Here are things you can do:

  • Detail all your described symptoms
  • Tell your medical history, past surgeries or procedures taken, and illnesses made you bedridden 
  • Do detail if you recently have long trips or journeys involving flights or long-distance driving
  • Medical history of your parents or siblings, which may indicate risk of heart disease or cancer that may cause blood clots or tumors
  • List of medications or supplements you take

In the hospital, the doctor listens for sounds in your lungs and heart and check your leg for any signs of swelling. A leg with deep vein clot may look swollen, tender and warm.

5 Treatment

Prompt treatment of pulmonary embolism reduces the risk of serious damage to the lungs, prevents the formation of new blood clots, and prevents death.


The doctor may give you the following medications:

  • Anticoagulants or blood thinners work to prevent the formation of additional blood clots. Heparin is a very effective and quick-acting blood thinner that can be injected or administered in the vein. Another anticoagulant is warfarin, which is available in oral form and often given several days after heparin injection for continued blood-thinning action. There are newer anticoagulants that act quicker, can be administered by mouth, and have fewer interactions with other drugs. The side effect of blood thinners is increased the risk of bleeding.
  • Thrombolytics are medicines that dissolve clots, and can help clear blood clots that cause pulmonary embolism. Thrombolytics are administered in your vein for quick onset of effect. However, thrombolytics can cause sudden bleeding so it is reserved only for emergency or life-threatening situations.

The doctor may resort to surgery, especially if the patient cannot take drugs or the given medication is not working fast enough. One procedure removes very large clots in the lung using a thin, flexible tube inserted into your blood vessels.

It may be done with another procedure that puts a filter in the main vein in the body (inferior vena cava) so to stop blood clots from entering the heart and getting into the lungs. The filter is inserted into a blood vessel in the neck through a catheter, and can be removed when not needed.

6 Prevention

Preventing deep vein thrombosis can significantly reduce your risk of having a pulmonary embolism.

Hospitals understand that patients are at risk of deep vein thrombosis, and so are aggressive employing measures to prevent blood clots from occurring.

Here are those measures:

  • Early ambulation. Your doctor may strongly encourage you to move or even stand up a day or two after surgery, even if you are still in pain. Ambulation is a simple way of preventing blood clots forming in your bloodstream, and also makes recovery quicker.
  • Elevating your legs enables blood to flow easier through the aid of gravity, thereby reducing blood pooling that forms blood clots.
  • Compression stockings compress the veins of your leg to avoid blood from pooling. 
  • Pneumatic compression uses air bags around your leg that inflates and deflates every few minutes to prevent blood clots from forming.
  • Anticoagulant drugs are given to people at risk of forming blood clots. It is often given to patients that sustained stroke, heart attack or cancer

Preventing deep vein thrombosis in the first place is key to prevention of pulmonary embolism.

Here are the following measures:

  • Take frequent breaks when sitting to circulate blood in the legs. If you are in an aircraft, stand up and move around every hour. Take a short break every hour of driving and walk around.
  • Fidgeting in your seat is also recommended. 
  • Plenty of fluids can help prevent dehydration that contributes to the formation of clots. Drink water often when driving or have a bottle of water during flights.
  • Support stockings might be good for you if you are prone to blood clots. Your doctor can help you choose good support stockings.

7 Risks and Complications

There are several risks associated with pulmonary embolism.

Anyone can develop blood clots that may cause pulmonary embolism.

However, certain conditions can put you at increased risk:

  • Heart disease, especially those that cause heart failure or arrhythmias, makes it more likely to form blood clots that can cause pulmonary embolism.
  • Certain cancers, like pancreatic, ovarian, lung, and metastasized cancers, can cause increased production of substances that causes blood clots. Some cancers can cause parts of tumors to enter the bloodstream that can clog an artery in the lung. Chemotherapy may also cause blood clot formation.
  • Anyone at bed rest is a risk factor for deep vein thrombosis.
  • Engaging in long journeys including flying and driving can make you immobile that slows down blood flow, which is a risk factor for blood clots.
  • Recovery from surgery is a known risk factor for deep vein thrombosis. Surgery of the hip and knee is particular for increasing the risk of clots because procedures can cause tissue debris to enter the bloodstream. Staying in bed for too long after surgery using general anesthesia can also cause deep vein thrombosis.
  • Obesity is a common risk factor for blood clotting. Reduced physical activity caused by obesity increases the tendency for blood clots. 
  • Pregnancy is a risk factor because the growing uterus may press against the veins in the pelvis, causing blood to pool and form clots.
  • Use of estrogen, like during hormone treatment for menopause and use of birth control pills, has increased the risk of blood clotting as a side effect.

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