Deep vein thrombosis (DVT) occurs when a blood clot forms in a vein, usually in the legs or pelvis. DVT is also known as venous embolism, thrombophlebitis, or phlebothrombosis. DVT is more likely in patients who have undergone orthopedic surgery, pelvic surgery, or abdominal and thoracic surgery. Patients with cancer and other chronic diseases such as heart disease, including those who have had a recent heart attack, are also at high risk of developing DVT.

DVT can be chronic, with recurring episodes. The three factors that contribute to DVT are:
1) changes in the content of the blood that clots more quickly,
2) radical changes in blood flow and
3) irritation or damage to the lining of blood vessels (which can be caused by high blood pressure).

DVT is caused by the formation of blood clots in the blood vessels, which form where blood flow in the veins is restricted. This most often occurs in pockets in the deep veins of the legs or pelvic veins that are weakened or damaged. In some cases, the development of deep vein thrombosis occurs in the arm near the shoulder, a condition known as Paget-Schrötter disease.

The most notable symptoms of DVT include swelling, pain, and redness of the affected limb. In some cases, the veins visible near the surface of the skin may be inflamed. However, these external symptoms usually occur in less than half of the patients. Part of the danger of the disease is that it is often silent. It makes sense for people with a family history of DVT to monitor their situation and undergo regular tests.

Symptoms of pulmonary embolism, a life-threatening complication of DVT, are: chest pain that worsens with coughing or deep breathing, coughing up blood, dizziness or fainting, unexplained shortness of breath, and rapid breathing with increased pulse. A person with these symptoms should seek immediate medical attention, especially if they have a history of deep vein thrombosis.

Depending on the severity, DVT can be treated with drug therapy. Bed rest with the legs elevated is required until the condition improves. Gradient elastic stockings, sometimes called compression stockings, may be necessary for up to a year, and the patient should avoid sitting or standing for prolonged periods.

Drug therapy to reduce the risk of blood clots is the most common treatment for DVT. The most commonly used drugs are anticoagulants that slow the growth of blood clots. Heparin is a common injectable blood thinner and is used together with Coumadin for at least three months.

Patients with severe deep vein thrombosis may receive thrombolytic therapy to try to dissolve the clots. Tissue plasminogen activator is the most widely used thrombolytic therapy. Thrombolytics increase the risk of severe bleeding, so they are only used when the patient’s venous thrombosis is life-threatening.

Another treatment is a filter that can be inserted into the vena cava to prevent blood clots from reaching the heart or lungs. Filters are more common in patients who are unable to use blood-thinning medications or are at increased risk for falls or are being treated for multiple trauma. Patients who do not respond quickly enough to drug therapy may also need a filter.

Of course, people at risk for DVT can greatly help themselves by losing weight, quitting smoking, and exercising regularly (especially exercises focused on the legs and calves). Those who fly frequently or sit for long periods should make an effort to get up from their sitting position every 2 hours to stretch and walk for a few minutes. They should also drink a lot of water during the trip. The idea is to keep the blood flowing, especially in the legs.

DVT can be life-threatening and must be treated. Anyone, especially those with a family history, experiencing the symptoms associated with deep vein thrombosis needs immediate medical attention.