Following months of grounded travel, many Americans are returning to the skies this holiday season to visit friends and family. But these long-haul journeys can have more risks than just lost luggage, and if you are someone at risk for vascular disease, it is important to understand the warning signs of deep vein thrombosis when travelling long distances.

Deep vein thrombosis (DVT) is a medical condition that occurs when a blood clot forms in a deep vein, usually the lower leg or thigh, though it can occur in the arm or pelvis as well. DVT can develop when a person is stationary for too long, leading to a slowing down of blood flow, which can result in a blood clot. Symptoms can include pain in the area and swelling, though sometimes DVT can occur with no symptoms. Nearly 2 million Americans are affected by DVT each year, and nearly 200,000 die from related complications.

“Deep vein thrombosis can be very serious, as the blood clot can break loose, travel through the bloodstream and cause a pulmonary embolism in the lungs,” said Dr. William Brown, MD, an interventional cardiologist with Memorial Hermann Medical Group (MHMG).

Deep vein thrombosis can be preventable, however, with both long-term lifestyle changes and short-term interventions, such as regular movement during a long flight.

“Try to get up, stretch and walk around every one to two hours if you are on a flight or a long-distance car trip,” Brown said. “This helps move your muscles to prevent blood clots. If you are unable to stand, try a stationary workout. Extend both legs forward and move your feet in a circular motion clockwise then counterclockwise, followed by squeezing each knee to the chest for 15 seconds at a time.”

Brown suggested following that workout with stretching the calves by placing both feet on the floor and pointing toes upward, then doing the opposite by gluing your toes to the floor and lifting your heels as high as possible.

In addition to movement, hydration is also important, so individuals should drink plenty of liquids and avoid alcohol on long journeys, as it can be dehydrating and may lead to poor blood flow. Another helpful precaution to avoid DVT is the use of compression socks or stockings, which are particularly important for seniors or those with known circulation problems.

DVT is a form of vascular disease, which is a condition that affects blood vessels, including veins and arteries. The most common vascular diseases are peripheral artery disease (PAD), carotid artery disease, aortic disease, venous disease, carotid dissections and aortic aneurysms, all of which can put individuals at a higher risk for strokes and heart attacks.

“Risk factors such as having diabetes, smoking, obesity, high cholesterol, high blood pressure and family history of vascular disease and/or diabetes all put a person at higher risk for developing a vascular disease,” Brown said. “While these conditions are more common in adults over age 50, many vascular diseases begin with unhealthy lifestyles at an early age. Atherosclerosis for example, which is the build-up of fats and cholesterol inside artery walls, can begin in the teen years, so it is critical that individuals follow heart-healthy diets and begin healthy habits early in their lives.”

Brown added that diet and lifestyle changes can benefit anyone no matter their age, and that smoking cessation and weight management can greatly reduce one’s risk of developing DVT or any vascular disease.

“Be aware of the warning signs and keep up with your primary care appointments so that your physician can monitor your vascular health,” Brown said. “And if you are at high risk, or if you are elderly, pregnant, or have a family history of DVT, remember the importance of movement during long periods of inactivity, and understand the warning signs so that you can seek care immediately, if needed.”