Deep vein thrombosis (DVT) is a condition that occurs when a blood clot forms in a vein deep inside a part of the body. It mainly affects the large veins in the lower leg and thigh, but can occur in other deep veins such as in the arms and pelvis.
Alternative Names
DVT; Blood clot in the legs; Thromboembolism; Post-phlebitic syndrome; Post-thrombotic syndrome; Venous - DVT
Causes
DVT is most common in adults over age 60. But it can occur at any age. When a clot breaks off and moves through the bloodstream, it is called an embolism. An embolism can get stuck in the blood vessels in the brain, lungs, heart, or another area, leading to severe damage.
Blood clots may form when something slows or changes the flow of blood in the veins. Risk factors include:
- A pacemaker catheter that has been passed through the vein in the groin
- Bed rest or sitting in 1 position for too long, such as plane travel
- Family history of blood clots
- Fractures in the pelvis or legs
- Giving birth within the last 6 months
- Pregnancy
- Obesity
- Recent surgery (most commonly hip, knee, or female pelvic surgery)
- Too many blood cells being made by the bone marrow, causing the blood to be thicker than normal (polycythemia vera)
- Having an indwelling (long-term) catheter in a blood vessel
Blood is more likely to clot in someone who has certain problems or disorders, such as:
- Cancer
- Certain autoimmune disorders, such as lupus
- Cigarette smoking
- Conditions that make it more likely to develop blood clots
- Taking estrogens or birth control pills (this risk is even higher with smoking)
Sitting for long periods when traveling can increase the risk for DVT. This is most likely when you also have 1 or more of the risk factors listed above.
