Deep vein thrombosis (DVT) is the formation of a blood clot in the deep veins of the body, usually in places where blood flow is slower, such as the leg. Blood clots are semi-solid masses of sticky blood cells that form when a blood vessel is damaged. The body creates blood clots as a normal response to blood vessel damage in order to seal a break and stop bleeding. When the clot stays where it was formed, it is called a thrombus and may cause damage by preventing the flow of oxygen and blood to an organ. Or, it can break off and travel to other parts of the body causing damage in other areas of the body.

When a clot forms in the veins of the leg, there are often no symptoms. If there are symptoms, they usually occur in the leg with the clot. If you experience any of the following signs, and they cannot be explained by exercise or injury, you may have a DVT:

  • pain or tightness
  • swelling
  • increased warmth
  • changes in skin colour (redness)

Although DVTs often occur in people over the age of 60, they can occur in younger people as well.

You may have an increased risk of developing a DVT if you:

  • are immobilized for long periods of time (prolonged sitting during travel, or prolonged bed rest due to illness)
  • have had recent surgery
  • sustain fractures or trauma
  • have varicose veins
  • have given birth within the last 6 months
  • take certain medications, such as estrogen or the birth control pill
  • have certain medical conditions such as bone marrow disease (e.g., polycythemia vera), cancer, or blood clotting disorders

Although DVTs themselves are not life-threatening, when they break off and travel to other parts of the body (embolize), they can cause severe organ damage, which could be fatal. Pulmonary embolism (a clot in the lung), heart attacks, and strokes are all complications of blood clots in veins or arteries that could result in death.

Get immediate medical help if you experience chest pain, difficulty breathing, fainting, or severe leg pain.

DVTs can be treated effectively, although there is a risk that it can happen again. For treatment and prevention, medications to thin the blood, such as heparins or warfarin, are prescribed.

To help prevent DVT, avoid long periods of immobility such as long car trips or airplane flights. Try to walk around and stretch for a few minutes every hour or so. Elevate your legs above your heart level if possible, and if you have a history of blood clots, wear support stockings or socks.

Prevention of blood clots is the best way to deal with the problems of heart disease and stroke. It is important to reduce or quit smoking and to control high blood pressure. High cholesterol levels also present a risk for blood clots and may be checked by your doctor. A healthy diet and regular exercise can help to reduce the risk of heart attack and stroke.

Written and reviewed by the MediResource Clinical Team