Deep Vein Thrombosis (DVT)
What is deep vein thrombosis?
Deep vein thrombosis (DVT, also called venous thrombosis) is a blood clot that develops in a deep vein (the veins that run through the muscles). The clot may partially or completely block blood flow through the vein. Most DVTs occur in the lower leg, thigh or pelvis, although they also can occur in other parts of the body including the arm, brain, intestines, liver or kidney.
The blood clot has the potential to break free and travel through the bloodstream, where it can become lodged in the blood vessels of the lung (known as a pulmonary embolism). This can be a life-threatening condition. Therefore, prompt diagnosis and treatment are necessary.
DVT can also lead to complications in the legs which develop years after the DVT occurred. This is referred to as chronic venous insufficiency or the post-thrombotic syndrome. This condition is characterized by pooling of blood, chronic leg swelling, increased pressure, increased pigmentation or discoloration of the skin, and leg ulcers known as venous stasis ulcer.
What is the difference between DVT and a superficial venous thrombosis?
A superficial venous thrombosis (also called phlebitis or superficial thrombophlebitis) is a blood clot that develops in a vein close to the surface of the skin. These types of blood clots do not usually travel to the lungs unless they move from the superficial system into the deep venous system first. They usually present as a lump which is hard, red and tender. It is often in a pre-existing varicose vein.
What are the symptoms of DVT?
DVT most commonly occurs in just one leg or one arm. Not everyone with DVT will experience symptoms, although when present, they may include:
- Swelling of the leg or arm (sometimes it occurs suddenly)
- Pain or tenderness in the leg that may only be present when standing or walking
- Feeling of increased warmth in the area of the leg or arm that is swollen or that hurts
- Redness or discoloration of the skin
- Enlargement of the superficial veins in the affected leg or arm
Symptoms of a pulmonary embolism include:
- (Sudden) shortness of breath
- Sharp chest pain, often aggravated by coughing or movement
- Pain in the back
- Cough with or without bloody sputum
- Excessive sweating
- Rapid pulse or breathing
- Light-headedness or passing out
Some people only find out they have DVT after the clot has moved from the leg or arm and travelled to the lung.
It is important to notify your doctor immediately or go to the emergency room if you have symptoms of a pulmonary embolism or DVT. Do not wait to see if the symptoms will “go away.” Get treatment right away to prevent serious complications.
Who is at risk?
The following conditions may increase your risk of developing DVT:
- An inherited (family) condition that increases the risk of blood clotting
- Cancer and some of its treatments (chemotherapy)
- Limited blood flow in a deep vein, due to injury, surgery, or immobilization
- Long periods of inactivity that decrease blood flow, such as:
- Sitting for a long period of time on long trips in a car, truck, bus, train, or an airplane
- Immobility after surgery or a serious injury
- Pregnancy, and the first 6 weeks after giving birth
- Being over age 40 (although deep vein thrombosis can occur in any age group)
- Being overweight
- Taking birth control pills or hormone therapy, including for postmenopausal symptoms
- Placement of central venous catheters through the arm or leg
- People with varicose veins have an increased risk of DVT
Diagnosis of DVT
Your doctor will ask you questions about your medical history and perform a physical exam as part of your diagnostic evaluation. Several tests will also be performed.
A duplex venous ultrasound is the most common test used to diagnose deep vein clots. It is used to evaluate the blood flow in the veins and to detect the presence and specific location of blood clots.
Other tests can be used such us CT or MRI. Also your doctor might organize special blood tests to find out the cause of the blood clot especially if there is no obvious reason or if it is not the first time you have blood clots.
How is DVT treated?
Depending on your condition, you may be admitted to the hospital for treatment, or you may receive treatment as an outpatient.
Treatments include medications (blood thinners), compression stockings, elevation of the affected leg, and diagnostic tests. The main goals in treating deep vein thrombosis are to:
- Stop the clot from getting bigger
- Prevent the clot from breaking off and moving to your lungs
- Reduce the risk of another blood clot
- Prevent long-term complications of the blood clot