“Compression socks work by applying a constant pressure to the ankle and calf area,” explains Dr. Doug Tumen, a podiatrist at Hudson Valley Foot Associates in Kingston, New York, and the author of Ask the Foot Doctor: Real-Life Answers to Enjoy Happy, Healthy, Pain-Free Feet. “This prevents pooling of blood in the legs, which is a risk factor for a blood clot. Arteries bring the oxygenated blood pumped from the heart to all areas of the body while the veins work to bring the blood back to the lungs for fresh oxygen. The compression socks aid in this venous return.”