Extended sitting or inactivity can result in leg swelling. Whenever you sit for long intervals, for example with a plane or at a desk, blood flow slows down, and fluid can accumulate in the legs. This is usually called “sitting condition” or “travel-similar edema.” Varicose veins are a common indicator https://www.sgvascularctr.com/swollen-leg-why-do-i-have-it-and-what-can-i-do/