DVT is relatively rare, affecting about 900,000 people in the United States each year, according to the Centers for Disease Control and Prevention (CDC). But it can have serious health consequences. DVT happens when a blood clot forms in a vein deep in the body, usually in the lower leg or the thigh. If left untreated, the clot can break off and travel through the bloodstream to an artery in the lungs (known as a pulmonary embolism), blocking blood flow and potentially causing death. A clot can cause problems even if it remains in the leg. In rare cases, DVT may lead to a serious condition called phlegmasia. “If a leg DVT is extensive enough, it creates so much pressure within the leg that it impairs arterial blood flow into the leg,” says Deborah Hornacek, MD, a cardiologist at Cleveland Clinic. “There is risk of tissue injury and even limb loss if this emergency is not identified and intervened on quickly enough.”
Risk Factors for Deep Vein Thrombosis
Spotting deep vein thrombosis can be tricky, as the signs are sometimes mistaken for other conditions. Here are signs of DVT to look for:
The leg swells; this is the most common symptom.Usually, only one leg is affected.The area is painful and warm.Symptoms get worse over time, rather than dissipate as they would with a pulled muscle.
“On occasion, you can see below the skin that some of the superficial, smaller veins are dilated as they try to compensate and shift blood around that blockage,” says Andrea Obi, MD, a vascular surgeon at Michigan Medicine in Ann Arbor. If you have pain and swelling in your leg, consider whether you have any risk factors that make deep vein thrombosis a more likely cause. Risks for DVT include:
Recent surgery, particularly orthopedic surgeryA prior history of DVTHormone medications like birth control pills or hormone replacement therapyCancer or cancer therapyAn illness or injury that has caused you to be inactive for a long period of timeProlonged travel in a car or airplane
Age is also a risk factor. “We haven’t figured out why, but DVT seems to be a disease of age,” Dr. Obi says. “That risk seems to take off after age 45.” Obesity, smoking, and extensive large varicose veins can also be contributing factors, Dr. Hornacek says. Genetics may also play a role, “but the majority of blood clots are caused by ‘provoked’ or ‘situational’ factors,” Hornacek says. “That’s why it’s important to know family history, but it often plays less of a role than most people expect.”
How Is Deep Vein Thrombosis Diagnosed?
When you seek medical help for suspected DVT, your doctor will probably perform a physical examination of the affected leg to check for pain and swelling. He or she will also check for knots that can be felt, which may indicate a blood clot. “As you can imagine, there are many medical conditions that can cause pain and swelling, but the way we make the diagnosis of DVT is with something called a duplex ultrasound,” Obi says. An ultrasound is a test that uses sound waves to create pictures of the veins and arteries. “This allows us to use a nonradiation technology to look at the deep veins, so it’s not risky to the patient in any way,” Obi says. If the ultrasound doesn’t provide a clear picture, your doctor may order a venography, which involves injecting dye into a vein in the affected leg to make the vein visible on an X-ray. Signs of DVT can also be spotted through a D-dimer test, a blood test to check for a substance that is released when a blood clot breaks up.
Treatment for Deep Vein Thrombosis
If you are diagnosed with DVT, know that it is a treatable condition. Your doctor will likely prescribe anticoagulants, or blood-thinning medication, like warfarin, heparin, enoxaparin, fondaparinux, edoxaban, apixaban, dabigatran, or rivaroxaban. “Anticoagulation helps to impressively reduce the risk for PE (pulmonary embolism) by stabilizing the clot that is there and helping the body break it down over time,” Hornacek says. You may need to take blood thinners for several weeks or months. It’s important to take them exactly as your doctor prescribes. Thrombolytics, sometimes referred to as “clot busters” may also be given to dissolve the clot. These medications have a higher risk of causing bleeding than blood thinners, so they are used only in severe cases. Additionally, wearing compression stockings can help reduce the risk that blood will pool and clot and may also prevent the swelling associated with DVT. In cases of phlegmasia, patients will need surgery to remove the blood clot and restore flow, Obi says. Finally, patients who have been treated for DVT should take care to minimize the risk factors that led to the clot. “It’s a matter of staying active, being cognizant of not staying immobile for long periods of time, and staying well-hydrated,” Obi says. Additional reporting by Ashley Welch
