Prevent Legs and Feet from Swelling in Transit Cramped cabin conditions and long flights can result in swollen feet and legs. The cause? Decreased blood flow, which in extreme cases can lead to blood clots and a potentially life-threatening condition called deep-vein thrombosis. Developed with the guidance of doctors. Compression Stockings stimulate circulation through gradual compression to stop swelling and help guard against DVT. Nylon-spandex. Imported. Women's Solid Compression Knee-High Stockings Regular sizes S - L. Womens Plus size 1X Sizing Information: S (Shoe size 4 - 5, calf circumference up to 14") M (Shoe size 5 - 8, calf circumference up to 16") L (Shoe size 8 - 10, calf circumference up to 17") Plus size 1X (Shoe size 5 - 8, calf circumference up to 19").