There are three reasons for the increasing swelling after foot fracture: First, the ligaments are strained after the foot fracture, and the small blood vessels are ruptured, which will lead to bleeding, and the bleeding will gradually increase, leading to the swelling becoming more and more obvious. So it is necessary to apply cold compresses, which can effectively close the small blood vessels to avoid further increase in bleeding and reduce the formation of swelling. Second, after the injury, inflammatory lesions will be formed, gradually forming inflammatory edema, and inflammatory metabolites gradually exuded, leading to further aggravation of swelling. It usually takes 3-5 days to go through the edema period, and the phase is a progressive increase in swelling. Third, the failure to elevate the foot will lead to further increase of bleeding and exudation due to gravity, and often due to the lack of timely foot immobilization, resulting in further strain on the injured ligaments and tendons, leading to further increase of injury and swelling.