Pulmonary Embolism In Detail

Pulmonary Embolism (PE) Explained

What is a Pulmonary Embolism (PE)?

A pulmonary embolism (PE) is a life-threatening condition where a blood clot begins to move through the vessels of the body and lodges in an artery in the lungs. In some cases, multiple clots (emboli) can move to the lungs.

When the clot lodges in the artery, blood can no longer reach the area of the lung that is fed by that blood vessel. This condition is very serious and can result in death if not treated immediately. If the clot(s) are severe, the individual will require emergency medical treatment in order to survive and prevent further clots.

What Causes a Pulmonary Embolism?

In the vast majority of cases, a pulmonary embolism is caused by another type of blood clot, called a deep vein thrombosis or DVT. A deep vein thrombosis typically forms in the veins of the legs. These clots can start to move until they lodge in a vessel that is too small to allow the clot to move any further, typically the small arteries of the lungs.

Risk Factors For Pulmonary Embolism (PE)

Risk Factors for Pulmonary Embolism

Most pulmonary embolisms begin as deep vein thrombosis, so the risk factors are similar for the two conditions.

Risk factors for pulmonary embolism include:

  • Surgery: Having a surgical procedure is a risk factor for several reasons. For example, during the procedure, the patient is completely still due to anesthesia for an extended period of time, many hours in some cases. Also, after the procedure many patients experience pain with movement, so they may not walk as much as is typical.
  • Being Stationary: Sitting still for extended periods of time, such as during air travel or on a road trip, is a risk factor for blood clots forming in the legs.
  • Breaking a bone: It is possible to have an embolus form after a bone is broken, particularly the thigh (femur) bone.
  • Blood clotting disorders
  • Decreased mobility: This may include being bedridden or having difficulty walking.
  • History of previous blood clots
  • History of previous pulmonary embolism
  • Smoking/Tobacco: Tobacco use increases the risk of blood clots.
  • Pregnancy or Recent Pregnancy
  • Obesity
  • Hormone therapy: This includes hormone replacement therapy after menopause.
  • Birth control pills: Blood clots are a known risk of all birth control pills.

Pulmonary Embolism: Signs and Symptoms

Signs and Symptoms of Pulmonary Embolism

A pulmonary embolism can present signs and symptoms that range from barely notable to severe. In fact, some patients only notice the signs of the deep vein thrombosis that led to the pulmonary embolism and not the embolism itself. For this reason, the signs and symptoms of deep vein thrombosis that may seem unrelated to a lung condition, such as calf pain, are included in this list.

  • Difficulty breathing (dyspnea)
  • Coughing
  • Coughing up blood-tinged sputum
  • Shortness of breath
  • Chest pain
  • Wheezing
  • Leg pain
  • One leg that is larger than the other (typically the calf of one leg is swollen)
  • Feeling lightheaded
  • Feeling weak
  • Clammy or sweaty skin
  • Irregular heartbeat
  • Rapid heartbeat (tachycardia)

Pulmonary Embolism: Common Treatments

Pulmonary Embolism Treatments

The course of treatment for a pulmonary embolism varies based upon the severity of the embolus, the cause of the embolus, the number of emboli present, the general health of the patient and any medical condition that may affect the outcome of treatment.

  • Anticoagulation: Prescription medications that "thin the blood" and help prevent blood clots are typically given to prevent future clots and to prevent current clots from worsening. Coumadin and Heparin are medications frequently used for this purpose and often require frequent blood tests to obtain information about the appropriate dose. A newer class of drug, called oral direct factor Xa inhibitors, is becoming more common in the treatment of clots that have already formed.
  • Remove Clot: There are multiple ways to remove blood clots, ranging from minimally invasive procedures that are done by inserting tiny instruments into blood vessels and threading them through the vessel to the clot, to an emergency surgery to remove the clot.
  • Thrombolytics: Clot-dissolving drugs, known as thrombolytic agents, are given to dissolve clots that have already formed. This type of medication works well, but may not be able to be used in cases where there is a risk of bleeding. For example, a patient who has a pulmonary embolism after suffering severe trauma could be at risk for bleeding in another part of the body if given a thrombolytic.
  • Filter Placement: Known by a variety of names, including Inferior Vena Cava Filter, IVC, and Greenfield Filter, this is a tiny filter that is surgically placed in the large blood vessel that returns blood from the body to the heart. This filter is designed to "catch" tiny blood clots before they are circulated through the heart and on to the lungs. Most often, these filters can be placed using minimally invasive techniques.


National Heart, Lung, and Blood Institute. "What Is Pulmonary Embolism?" http://www.nhlbi.nih.gov/health/health-topics/topics/pe/