


Although anyone can develop deep vein thrombosis (DVT) and pulmonary embolism, factors such as immobility, cancer and surgery increase your risk.


Pulmonary embolism symptoms can vary greatly, depending on how much of your lung is involved, the size of the clots and your overall health — especially the presence or absence of underlying lung disease or heart disease.

Common signs and symptoms include:


Other signs and symptoms that can occur with pulmonary embolism include:

  • Clammy or discolored skin (cyanosis)
  • Fever
  • Excessive sweating
  • Rapid or irregular heartbeat
  • Lightheadedness or dizziness

When to see a doctor



Occasionally, substances other than blood clots can form blockages within the blood vessels inside your lungs. Examples include:

  • Fat from within the marrow of a broken long bone
  • Part of a tumor
  • Air bubbles

It's rare to have a single pulmonary embolism. In most cases, multiple clots are involved but not necessarily all at once. The portions of lung tissue 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.


Medical history


In addition, certain medical conditions put you at risk, such as:


Prolonged immobility




Surgery is one of the leading causes of problem blood clots, especially seen after joint replacements of the hip and knee. During the preparation of the bones for the artificial joints, tissue debris may enter the bloodstream and contribute to causing a clot. Simply being immobile during any type of surgery can lead to the formation of clots. The risk increases with the length of time you're under general anesthesia. For this reason, most people undergoing a type of surgery predisposing them to DVT will receive medication before and after surgery to prevent clot formation.

Other risk factors





Most cases of pulmonary embolism are initially evaluated in hospitals, emergency rooms or urgent care centers. If you think you might have a pulmonary embolism, seek immediate medical attention.

What you can do

You may want to write a list that includes:

  • Detailed descriptions of your symptoms
  • Information about your past medical problems, especially any recent surgeries or illnesses that kept you bedridden for several days
  • Information about the medical problems of parents or siblings
  • Medications you're taking
  • Questions you want to ask the doctor

What to expect from your doctor

During the physical exam, your doctor might inspect your legs for evidence of a deep vein clot — an area that's swollen, tender, red and warm. He or she will also listen to your heart and lungs and check your blood pressure.


Blood tests

Your doctor may order a blood test for the clot-dissolving substance D dimer in your blood. High levels may suggest an increased likelihood of blood clots, although D dimer levels may be elevated by many other factors, including recent surgery. In addition, blood tests may be done to determine whether you have an inherited clotting disorder.

Chest X-ray



A noninvasive "sonar" test known as duplex ultrasonography (sometimes called duplex scan, or compression ultrasonography) uses high-frequency sound waves to check for blood clots in your thigh veins. In this test, your doctor uses a wand-shaped device called a transducer to direct the sound waves to the veins being tested. These waves are then reflected back to the transducer and translated into a moving image by a computer. The absence of the presence of clots reduces the likelihood of DVT. If the upper thigh vessels are clear, the ultrasonography will also scan the veins behind the knee looking for residual clots. If clots are present, treatment likely will be started immediately.

CT scan


Pulmonary angiogram

This test provides a clear picture of the blood flow in the arteries of your lungs. It's 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 a definitive diagnosis.

In a pulmonary angiogram, a flexible tube (catheter) is inserted into a large vein — usually in your groin — and threaded through into your heart and on into the pulmonary arteries. A special dye is then injected into the catheter, and X-rays are taken as the dye travels along the arteries in your lungs.



MRI scans use radio waves and a powerful magnetic field to produce detailed images of internal structures. Because MRI is expensive, it's usually reserved for pregnant women (to avoid radiation to the fetus) and people whose kidneys may be harmed by dyes used in other tests.

Treatment is aimed at keeping the blood clot from getting bigger and preventing new clots from forming. Prompt treatment is essential to prevent serious complications or death.


  • Blood thinners (anticoagulants). These drugs prevent new clots from forming while your body works to break up the clots. 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, until it becomes effective, which can take days. A newer class of anticoagulants has been tested and approved for treatment of venous thromboembolism, including pulmonary embolism. These medications have the advantage of being given by mouth, without the need for overlap with heparin. Also, they work quickly and have fewer interactions with other medications. All blood thinners have side effects, with bleeding being the most common.
  • Clot dissolvers (thrombolytics). While clots usually dissolve on their own, there are medications given through the vein that can dissolve clots quickly. Because these clot-busting drugs can cause sudden and severe bleeding, they usually are 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 can also be used to position a filter into the body's main vein — called the inferior vena cava — that leads from your legs to the right side of your heart. This filter can help keep clots from being carried into your lungs. This procedure is typically reserved for people who can't take anticoagulant drugs or when anticoagulant drugs don't work well enough or fast enough. The catheter with the filter in the tip is usually inserted in a vein in your neck, and then into the vena cava. Some filters can be removed when they are no longer needed.



Prevention while traveling


  • Fidget in your seat. Flex your ankles every 15 to 30 minutes, or try rising up and down on your toes while standing. Don't sit with your legs crossed at the knees for long periods of time.
  • Wear support stockings. Your doctor may recommend these to help promote circulation and fluid movement in your legs. Compression stockings no longer look like something only a grandmother would wear — they're available in a range of stylish colors and textures. There are even devices, called stocking butlers, to help you put on the stockings.
March 18, 2015