Deep venous thrombosis is a blood clot that forms in a vein deep inside a part of the body. It mainly affects the large veins in the lower leg and thigh.
DVT; Blood clot in the legs; Thromboembolism; Post-phlebitic syndrome; Post-thrombotic syndrome
DVTs are most common in adults over age 60. But, they can occur at any age. When a clot breaks off and moves through the bloodstream, this is called an embolism. An embolism can get stuck in the brain, lungs, heart, or other 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 one 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
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
Blood is more likely to clot in someone who has certain problems or disorders, such as:
Take the medicine just the way your doctor prescribed it.
Ask the doctor what to do if you miss a dose.
Get blood tests as advised by your doctor to make sure you are taking the right dose.
Learn how to take other medicines and when to eat.
Find out how to watch for problems caused by the drug.
You will be given a pressure stocking to wear on your leg or legs. A pressure stocking improves blood flow in your legs and reduces your risk for complications from blood clots. It is important to wear it every day.
In rare cases, you may need surgery if medicines do not work. Surgery may involve:
Placing a filter in the body's largest vein to prevent blood clots from traveling to the lungs
Removing a large blood clot from the vein or injecting clot-busting medicines
Many DVTs disappear without a problem, but they can return. Some people may have long-term pain and swelling in the leg called post-phlebitic syndrome.
You may also have pain and changes in skin color. These symptoms can appear right away or you may not develop them for 1 or more years afterward. Wearing tight (compression) stockings during and after the DVT may help prevent this problem.
Blood clots in the thigh are more likely to break off and travel to the lungs (pulmonary embolus, or PE) than blood clots in the lower leg or other parts of the body.
When to Contact a Medical Professional
Call your health care provider if you have symptoms of DVT.
Go to the emergency room or call the local emergency number (such as 911) if you have DVT and you develop:
Guyatt GH, Akl EA, Crowther M, et al. Executive Summary: Antithrombotic Therapy and Prevention of Thrombosis. 9th ed. American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 suppl):7s-47s.
Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.