What are Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE)?

Deep vein thrombosis (DVT) occurs when a blood clot (thrombus) forms in one or more of the deep veins in your body, usually in your legs. Deep vein thrombosis can cause leg pain or swelling, but also can occur with no symptoms.

Doctors often refer to deep vein thrombosis (DVT) and pulmonary embolism (PE) as a single condition known as VTE, which stands for venous thromboembolism.  DVT and PE affect about 900,000 people in the United States every year, and are very serious conditions. In fact, PE is a medical emergency and can be fatal, but there are treatment options available and steps you can take to reduce the risk of recurrence.

DVT stands for deep vein thrombosis and is a condition in which one or more blood clots form in one or more of the deep veins in your body.  These clots form most often in the large veins of your legs or thighs.

PE stands for pulmonary embolism which means “pertaining to the lungs,” and embolism refers to a clot that forms in one part of the body and travels through the blood stream to another part of the body.  PE is a condition in which one or more of the pulmonary arteries in your lungs become blocked. In most cases, this blockage is caused by blood clots that form in the legs due to DVT and then travel to the lungs.

Deep vein thrombosis can develop if you have certain medical conditions that affect how your blood clots. It can also happen if you don’t move for a long time, such as after surgery or an accident, or when you’re confined to bed.

Deep vein thrombosis can be very serious because blood clots in your veins can break loose, travel through your bloodstream and lodge in your lungs, blocking blood flow (pulmonary embolism).

A DVT may well settle completely, as the thrombosis is dissolved by natural processes. If a DVT extends up the deep veins, two things can happen:

  • The thrombosis can become dislodged from the vein, and get carried through the main veins and heart to lodge in the lungs; this is called a pulmonary embolism. Small pulmonary emboli may cause chest pain, and sometimes coughing up of blood. Multiple or larger pulmonary emboli may cause breathlessness. A large pulmonary embolus which blocks the main blood vessels to the lungs can be fatal.
  • The thrombosis can cause chronic blockage in the deep veins or damage to their valves, leading to long term swelling and sometimes skin problems at the ankle.

What Causes Blood Clots?

The process begins whenever flowing blood comes into contact with specific substances in your skin or in blood vessel walls. When they touch, it usually means the skin or blood vessel wall is broken.

Waxy cholesterol plaques that form in arteries have these things inside, too. If the plaque breaks open, they’ll start the clotting process. Most heart attacks and strokes happen when a plaque in your heart or brain suddenly bursts.

Blood clots can also form when your blood doesn’t flow properly. If it pools in your blood vessels or heart, the platelets are more likely to stick together. Atrial fibrillation and deep vein thrombosis (DVT) are two conditions where slowly moving blood can cause clotting problems.


The symptoms of DVT

In about half of all cases, DVT occurs without any symptoms. When there are symptoms, they can include:

  • pain or swelling in the affected leg or thigh
  • skin of the affected area is warm to the touch
  • change in skin color of the affected area, such as redness

If you experience any of these symptoms, contact your doctor immediately.

The symptoms of PE

The symptoms of PE are serious and require immediate medical attention, as PE can be fatal. These symptoms include:

  • unexplained shortness of breath
  • chest pain that worsens when you cough or breathe deeply
  • coughing up blood
  • lightheadedness or dizziness
  • rapid pulse or breathing
  • sweating

Less common signs and symptoms of pulmonary embolism may include coughing, with or without blood; feelings of anxiety or dread; light-headedness or fainting; and sweating.

Call 911 or seek emergency medical attention immediately if you develop signs or symptoms of PE.

Some common myths about DVT and PE

Myth 1:  If you are young and healthy, DVT and PE won’t affect you.

Not true. While people over 60 years of age are more likely to develop DVT and PE, people of all ages can be affected.

Myth 2:  There is nothing you can do to reduce the risk of DVT and PE.

The fact is that you can reduce the risk of DVT and PE through early symptom recognition and management. Know the symptoms of DVT and PE, talk to your doctor about the risk factors for developing them, and seek emergency medical care immediately if you experience any of the symptoms.

What is the Treatment of DVT?

Most treatment for DVT can occur without hospitalization – this may be necessary however if there are extensive clots or there is a suspicion of pulmonary embolus. Blood thinning (anti-coagulation) is the main treatment for DVT and PE to prevent further blood clots. They can be in the form of an injection or tablets.

In very serious cases, a medication to dissolve the blood clot can be used but a vena cava filter may be used if you cannot take the medicine.

There is a significant risk of bleeding with this medication and you should discuss this carefully with your doctor.

What Can I Do to Prevent Further DVT?

There is now evidence that wearing below the knee graduated compression stockings reduces the chance of DVT for people with special risk factors.  Because so few people without risk factors ever develop DVT or pulmonary embolism as a result of long journeys, there is no definite evidence about other measures which reduce the risk.

Maintaining a healthy lifestyle is important to reduce the risk of further DVT. This includes:

  • quit smoking
  • maintain ideal body weight
  • regular exercise
  • maintain adequate hydration and legs movement, especially during long distance travel
  • selective use of compression stockings and low dose anticoagulant drugs in high-risk hospitalized patients
  • Move your legs: Don’t sit with your legs bent for hours on end
  • Stretch your legs out from time to time, and move your feet up and down at the ankles
  • Stand up to stretch the legs now and then. Stretching and moving your legs stops blood stagnating in the deep veins of the calf, and is the simplest and most effective thing you can do
  • Avoid excessive alcohol, which tends to cause dehydration
  • Compression stockings