A swollen foot is usually a sprained ankle. When ankle sprain occurs and you want to reduce the swelling, the first thing to do is to protect the injured part by braking to avoid secondary injury to aggravate the local swelling. You can sit or lie down directly, do not walk or strenuous activities, ensure rest, and at the same time elevate the sprained side of the leg to promote blood return, but also to prevent blood clots, swelling and pain relief. Secondly, within 48 hours of the injury, it belongs to the acute injury period after the ankle sprain, local cold compress should be applied immediately, which can effectively promote local small blood vessel contraction to relieve local bleeding or swelling. Each cold compress should not be too long and avoid direct contact with the skin with an ice pack. You can use a towel or clothes to wrap the ice pack and apply it to the swelling to prevent frostbite. Local massage, rubbing and hot compresses should be avoided in the acute phase to avoid aggravating the symptoms. And 48 hours after the injury can be local hot compresses or physical therapy to promote local tissue healing and help reduce swelling. If there is a ligament injury it is recommended to carry out plaster fixation or use joint immobilizers, bandages with pressure to help fixation for 2-3 weeks and good braking, which can help relieve local swelling. Local medication can be applied to activate blood circulation and remove blood stasis, or apply ointment with pain-relieving and swelling-reducing effect, and change medication regularly to help reduce swelling. If the swelling in the ankle persists or if there is severe pain, it is recommended to seek medical attention promptly. There may be a risk of fracture and surgery is required if necessary.