If you’ve experienced deep vein thrombosis (DVT), a blood clot that forms in a deep vein, you’ll want to be aware of potential complications, including the risk of a future clot.
The odds of having another DVT or pulmonary embolism (PE), in which a blood clot travels to the lungs, will depend on a variety of factors. For example, if a clot occurred from a temporary risk factor like surgery or trauma, it’s not likely to have recurrent DVT, according to the National Blood Clot Alliance. But if the blood clot occurred spontaneously without any risk factors, there’s a 30 percent chance another clot will develop over the next decade, the organization reports.
One of the biggest risk factors for recurrent DVT or PE is cancer. According to a research review published in the journal Blood Advances, individuals with cancer have a two- to ninefold increased risk compared with those without cancer.
However, even if you’re at an increased risk for recurrent DVT, there are a number of changes you can make in your life to reduce your chances.
DVT Risk Factors
DVT stems from a number of different causes. According to the National Heart, Lung, and Blood Institute, blood clots may form because of damage to the lining of a vein or tissue, because your blood is thicker than normal, or as the result of slow or stagnant blood flow.
Whether it’s the first instance or recurrent DVT, Teresa L. Carman, MD, director of vascular medicine at University Hospitals Cleveland Medical Center, notes that risks for DVT include:
- Genetic risk of clotting
- Older age
- Periods of immobility, such as taking long-haul flights or bed rest while in a hospital, nursing home, or following surgery
- Injury to vessels (which may result from catheter use or pacemaker)
- Hormone use or pregnancy
- Smoking
- Obesity
- Medical conditions, including cancer and immune disorders like lupus
Severe illness, such as infection with SARS-CoV-2, the virus that causes COVID-19, is also associated with increased risk of DVT. According to a study published in April 2022 in The BMJ, this increased risk remains for up to three months after COVID-19 infection, while the risk of a PE remains for up to six months.
Medication and Stockings for DVT
If you have had DVT, your doctor may prescribe medication to help prevent a recurrence.
“In patients at increased risk for recurrent DVT, ongoing anticoagulant use is prescribed — as long as there is a low-to-moderate overall bleeding risk,” Dr. Carman says.
Some people will be able to stop taking this blood thinning medication with a doctor’s permission about three to six months after their episode and take it again only during periods of high risk, such as surgery, according to clinical practice guidelines published in 2020 by the American Academy of Cardiology. Others may need to take blood thinners for a longer time to prevent DVT.
Your doctor might also recommend compression stockings, which lightly squeeze the legs and help blood flow. Usually a 20 to 30 millimeters of mercury (mmHg) stocking is recommended, Carman says. “This is a prescription grade compression,” she notes. “If a patient can not tolerate 20 to 30 mmHg stocking then a 15 to 20 mmHg stocking would be advised.”
Your doctor will help you determine which compression stocking is right for you.
Additionally, your doctor may recommend further testing to determine whether you have an underlying condition that increases your DVT risk. If you do, your treatment plan will also need to address this condition.
7 Ways to Reduce Recurrent DVT Risk
Follow these steps to reduce your risk of having another DVT:
- Take medications as prescribed. Taking blood-thinning medication according to your doctor’s instructions should help reduce your risk.
- Check in with your doctor. As your overall health status changes, make sure that all your doctors know about your DVT risk so they can help you with any treatment adjustments you need. For example, knowing about your DVT risk might cause your doctor to make different recommendations regarding hormone treatments, cancer treatment, or surgery.
- Get fit. Being more physically active and achieving a normal weight could help reduce your risk. How much you should exercise or how quickly you should lose weight will depend on your current health and fitness, so work with your medical team to develop an exercise program that suits your situation.
- Stop smoking. Tobacco use may be a cause of DVT, says Carman. And smoking cigarettes has been shown to multiply the DVT risk from other factors, like being obese, according to research published in PLoS Medicine.
- Keep good records. Take note of when you had your DVT, where in your body it occurred, and how it was treated. This information could help doctors better manage your treatment for other conditions.
- Stay in motion. In addition to doing regular exercise like walking or swimming, you should try to be active throughout the day, especially during long trips by car or plane. “On flights, staying hydrated, doing foot and ankle mobility exercises and periodic walking may be helpful,” Carman says. In general, if you sit for long periods, get up and walk or stretch every hour or so. If you’re in a situation where you can’t move easily on your own, talk with your doctor or physical therapist about how to move.
- Be cautious with leg massage. People who are in treatment for DVT could loosen a clot with vigorous massage, according to the University of Texas at Austin’s University Health Services. Check with your medical team to find out whether some form of massage is an option for you and, if so, what technique to use. However, “once a patient is past the acute DVT (about six weeks to three months), there should be no contraindication to lower extremity massage,” Carman says.
