Deep Vein Thrombosis (DVT) Overview
DVT or deep vein thrombosis is the formation of a blood clot in any deep vein. It usually develops in the calf or thigh muscle. It can block the flow of blood either partly or completely causing swelling and chronic pain in the affected area. It can also lead to damage of the valves in blood vessels making it difficult for the person to move. In some cases, the blood clot can break free and travel through the blood to major organs including the heart and lungs where it can cause damage and even lead to the death of the person in just a few hours.
Signs and Symptoms of DVT
In about 50% of DVT cases, there are no symptoms which can be very dangerous and has actually caused the death of many people. Watch out for the following symptoms of DVT especially if they occur suddenly:
- Swelling in one or both legs.
- Pain or tenderness in one of both legs. It usually occurs only when standing or walking.
- Warmth in the skin of the affected legs.
- Red or discoloured skin in the affected legs.
- Visible surface veins that are not present before.
- Fatigue of the legs.
If a blood clot breaks free and reaches the lungs, it is referred to as a pulmonary embolism which can be fatal. It may not cause symptoms but if you suddenly experience coughing which may produce blood and sharp chest pain, shortness of breath or severe light-headedness, you need to go to an emergency room or call 911 as soon as possible.
Causes and Risk Factors
These surgeries increase* risk for DVT:
- Surgery that reduces* blood flow to any part of the body
- Major surgery involving a hip, knee, calf, leg, abdomen or chest
- Orthopaedic surgery of any kind
Other Cause of DVT
- Injury that reduces* blood flow to any part of the body
- Cancer (even during treatment)
- Previous history of DVT or pulmonary embolism
- An inherited condition which increases* blood clotting
- Paralysis due to spinal cord injury
- Use of hormone therapy especially in menopausal women who are smokers
- Pregnancy or recent child birth especially by C-section
- Varicose veins
- History of heart attack, congestive heart failure or stroke
- Inflammatory bowel disease
- Inactivity for prolonged periods
- Sitting for prolonged periods
- Long car trips or plane flights
- Carrying extra weight
- Use of birth control pills or patches
Tests and Diagnosis
In order to diagnose deep vein thrombosis, the doctor will ask a series of questions about the symptoms. A physical exam will also be conducted to check for swelling, tenderness or discoloration. If it is likely that there is a blood clot, the doctor may suggest further testing which may include the following:
- Ultrasound – A transducer is placed over the part of the body suspected to have a blood clot sending sound waves to the area. As the sound waves travel through tissue and reflect back, a computer transforms the waves into a video image on a screen. The clot may be visible in the image. In some cases, a series of ultrasounds are required to determine if the blood clot is growing or to ensure that a new one is not developing.
- Blood Test – Almost all individuals with severe deep vein thrombosis have an increased blood level of D dimer which is a clot-dissolving substance naturally produced by the body.
- Venography – A contrast agent or dye is injected into a large vein in the ankle or foot. An X-ray is then conducted to create an image of the veins in the affected area to look for clots. In most cases, this is not necessary because an ultrasound can confirm the diagnosis.
- CT or MRI Scans – Both of these can provide a visual image of the veins showing if there is a clot. Sometimes, a clot is found accidentally when these scans are performed for other purposes.
Treatments and Diagnosis
The main purpose of DVT treatment is to prevent the clot from becoming bigger while also preventing it from breaking loose and causing pulmonary embolism. Then, the goal becomes to reduce* the chance that a deep vein thrombosis will happen again. The treatment options for DVT include the following:
- Blood Thinners – These are medications called anticoagulants which decrease* the ability of the blood to clot. Blood thinners don’t break up existing clots but prevent them from getting bigger and reduces* the risk of developing other clots.
- Clot busters – This is for more serious forms of deep vein thrombosis or pulmonary embolism or if other medications are not working. One such group of medications are called thrombolytics which are drugs that are also called tissue plasminogen activators (TPA). They break up blood clots when given through an IV line or through a catheter placed directly into the clot.
- Filters – For people who cannot take medicines to thin the blood, a filter may be inserted into a large vein in the abdomen. The filter prevents clots that break loose from reaching the lungs.
- Compression Stockings – These are for preventing swelling associated with deep vein thrombosis. The stockings put pressure on the feet and legs which help lower the chance that blood will pool and clot in the area.
Related Video – Deep Vein Thrombosis Treatment at Stanford Hospital – Laura Resnansky’s Story
Precautions and Self Care
Once you already have received treatment for DVT, you need to be careful with your diet and look for signs of excessive bleeding. You should also take steps to prevent another DVT from occurring. Check in with your doctor regularly and take your blood thinners and other medications as prescribed by your doctor. Exercising regularly can help cut your risk of another DVT but get the go signal from your doctor first. You may need to wear compression stockings if recommended by your doctor. Do not sit still for prolonged periods and make the necessary lifestyle changes like living a more active lifestyle and quitting smoking.
- "What are the signs and symptoms of deep vein thrombosis?". National Heart, Lung, and Blood Institute. 28 October 2011. Retrieved 15 April 2012.
- Scarvelis D, Wells P (2006). "Diagnosis and treatment of deep-vein thrombosis". CMAJ 175 (9): 1087–92. doi:10.1503/cmaj.060366. PMC 1609160. PMID 17060659. 
- Bates SM, Jaeschke R, Stevens SM, et al. (2012). "Diagnosis of DVT: Antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines". Chest 141 (suppl 2): e351S–e418S. doi:10.1378/chest.11-2299. PMC 3278048. PMID 22315267.