A deep vein thrombosis is a blood clot that forms in the major veins of the body – usually the legs. Life-threatening complications can arise from DVT when blood clots dislodge, travel in the bloodstream, and then lodge in other veins or arteries causing a blockage. This can be life threatening, especially when the embolism occurs in the lungs, heart, or brain. Pulmonary embolism (a blood clot in the lung) is the most common of these serious DVT complications.
Veins are blood vessels that carry blood from the tissues of the body back to the heart. Veins that lie just beneath the skin surface are referred to as "superficial veins" while veins found deep inside the muscles are referred to as "deep veins". Other veins connect the superficial and deep veins, allowing blood to flow between them.
When a blood clot occurs in a vein it is referred to as a venous thrombosis. A DVT is a blood clot that occurs in the deep veins. DVTs can occur in any of the deep veins but most commonly occur in the leg veins. The clot will either partially or completely block the flow of blood through the affected vein. When the blood clot is associated with inflammation of the vein it is referred to as thrombophlebitis.
A DVT does not always cause symptoms. If symptoms do occur, the first symptom is usually a cramp-like aching pain in the affected muscles. This pain might worsen when exercising but does not subside with rest. Symptoms of a DVT in the calf muscle may include:
If a DVT is suspected – even if symptoms are mild – it is important to seek medical attention promptly. Accurate diagnosis and appropriate treatment of a DVT are necessary to reduce the risk of potentially life-threatening complications, such as pulmonary embolism.
Because a DVT can occur without any obvious symptoms, diagnosis can sometimes be difficult. Initially, the doctor will examine the affected area and take a full medical history. The doctor may recommend a blood test called a D-Dimer, which measures a protein essential for blood clotting. If the D-Dimer test is positive, further tests to confirm the diagnosis are likely to be ordered.
The most common diagnostic test for DVT is an ultrasound scan. The specific type of scan used is called a doppler ultrasound, which determines how fast blood is flowing through a blood vessel. The scan is painless and is able to detect up to 95% of DVTs.
The immediate goal of treatment for a DVT is to limit the size and movement of the clot, and to prevent complications. Treatment will depend on the location and severity of the clot. Some small clots may resolve spontaneously without treatment but a DVT is generally treated intensively. Admission to hospital for treatment and observation for signs of complications may be required.
Treatment may include: Medications, Compression stockings, Surgery