What is deep vein thrombosis
Deep vein thrombosis or DVT describes a blood clot that forms in the deep veins located in the arm or leg. It is important to know the body’s anatomy and function to understand why clots form in veins and why they can be dangerous.
There are two types of veins in the arm or leg; superficial veins and deep veins. Superficial veins lie just below the skin and are easily seen on the surface. Deep veins, as their name implies, are located deep within the muscles of the extremity. Blood flows from the superficial veins into the deep venous system through small perforator veins. Superficial and perforator veins have one-way valves within them that allow blood to flow only in the direction of the heart when the veins are squeezed.
A blood clot in the deep venous system of the leg or arm, in itself, is not dangerous. It becomes potentially life threatening when a piece of blood clot breaks off and embolizes, travels through the circulation system through the heart, and enters into one of the pulmonary arteries and becomes lodged. This can prevent blood from flowing properly through the lungs and decreasing the amount of oxygen absorbed and distributed back to the body.
Diagnosis and treatment of a DVT is meant to prevent pulmonary embolism.
Blood clots in the superficial veins do not pose a danger of causing pulmonary emboli because the perforator vein valves act as a sieve to prevent clots from entering the deep venous system. They are usually not at risk of causing pulmonary embolism
How do you get deep vein thrombosis?
Blood is meant to flow. If it becomes stagnant, there is a potential for it to clot. The blood in veins constantly forms microscopic clots that are routinely broken down by the body. If the balance of clot formation and clot breakdown is altered, significant clotting may occur. A thrombus can form if one or a combination of the following situations.
ImmobilityProlonged travel and sitting, such as long airplane flights (“economy class syndrome”), car, or train travel
Hospitalization, Surgery
Trauma to the lower leg with or without surgery or casting
Pregnancy, including 6-8 weeks after delivery of the baby
Obesity
Warning signs and symptoms of DVT
The signs and symptoms of DVT are related to obstruction of blood returning to the heart and causing a backup of blood in the leg. Classic symptoms include:

• Pain
• Swelling
• Warmth
• Redness
• Leg cramps, often starting in the calf
• Leg pain that worsens when bending the foot
• Bluish or whitish skin discoloration