What is deep vein thrombosis?
Deep vein thrombosis (DVT) occurs when a blood clot develops in a vein deep in the body. Deep veins are found within groups of muscles. The veins close to the skin are called superficial veins.
While these clots most often develop in the lower legs or thighs, they may appear in the upper body, such as the arms or other locations in the body. Deep vein thrombosis is a risk after any major surgery, but patients who have surgery of the legs or hips are at higher risk.
Deep vein thrombosis can pose a serious threat to health. Pieces of a clot can break off and travel through the bloodstream to the lungs. This is called a pulmonary embolism and can be fatal soon after it occurs. Deep vein thrombosis can also block blood flow in the veins, causing the blood to pool. This can cause swelling, pain, and permanent damage to the leg called post-thrombotic syndrome.
What is thrombophlebitis?
When a clot forms in a vein, inflammation of the vein may occur at the affected site. This is referred to as thrombophlebitis. Inflammation may be minimal, or may be more pronounced, causing swelling, redness, warmth, and tenderness at the site. When thrombophlebitis occurs, the body's response to inflammation may promote the formation of more clots.
What are the risk factors for deep vein thrombosis?
A risk factor is anything that may increase a person's chance of developing a disease. It may be an activity, diet, family history, or many other things.
Although these risk factors increase a person's risk, they don't necessarily cause the disease. Some people with one or more risk factors never develop the disease, while others develop the disease and have no known risk factors. Knowing your risk factors for any disease can help to guide you into the appropriate actions, including changing behaviors and being clinically monitored for the disease.
Risk factors related to or that may contribute to deep vein thrombosis and thrombophlebitis include, but are not limited to:
An inherited tendency that increases risk for blood clots
Age (older than 60)
Type A blood group
What causes deep vein thrombosis?
There are a variety of factors that contribute to the development of deep vein thrombosis:
Surgery, particularly surgery of the hip or leg, or abdominal surgery
A long period of bed rest or sitting for a long time (for example, on an airplane or in a car)
Certain diseases and conditions, such as:
Previous blood clot (thrombosis)
Intensive care treatment involving placement of a central venous catheter
People with cancer receiving chemotherapy
What are the symptoms of deep vein thrombosis?
Deep vein thrombosis occurs without symptoms about 50 percent of the time. When symptoms do occur, they may include:
Swelling in the leg
Red, discolored, or white skin
A cord in a leg vein that can be felt
Rapid heart beat (tachycardia)
More visible surface veins
Dull ache, tightness, tenderness or pain in the leg (these symptoms may only occur while walking or standing)
The symptoms of deep vein thrombosis may resemble other medical conditions or problems. Always consult your physician for a diagnosis.
How is deep vein thrombosis diagnosed?
In addition to a complete medical history and physical examination, diagnostic procedures for deep vein thrombosis may include:
Duplex ultrasound. This involves using high frequency sound waves to look at the speed of blood flow, and the veins. Occasionally a blood clot may be visualized by ultrasound. This procedure is noninvasive (the skin is not broken) and involves placing ultrasound gel on the affected area and then moving a handheld device across it. A picture of the blood flow is displayed on a monitor. Duplex ultrasound is the most commonly performed diagnostic test for DVT.
Magnetic resonance imaging (MRI). This diagnostic procedure uses a combination of large magnets, radio frequencies, and a computer to produce detailed images of organs and structures within the body, and is particularly effective in diagnosing deep vein thrombosis in the pelvis.
Venogram. This uses X-rays and intravenous (IV) contrast dye to visualize the veins. Contrast dye causes the blood vessels to appear opaque on the x-ray image, allowing the physician to visualize the blood vessels being evaluated.