Knee sprain swelling usually about 1~2 weeks can gradually subside, specific need to be based on the severity of sprain to comprehensive analysis. Knee sprain is a traumatic disease, its healing process can be divided into four periods, including bleeding, inflammation, repair, remodeling, different periods of performance more than different, the main manifestation is the local swelling of the joints, pain, the general duration of about 2 weeks. Patients with mild sprains, no obvious tears in the tissues around the knee joint, early ice treatment, and brake rest, the joint swelling can gradually subside in about 1 to 2 weeks; moderate to severe sprains, there are usually serious injuries to ligaments, tendons, meniscus and other serious injuries, usually need surgery to repair, in this case, the joint swelling usually need 2 weeks, or even more time to gradually subside. If the patient has a knee sprain, should go to the hospital as soon as possible, by the doctor according to the specific circumstances of the targeted treatment, in order to reduce the adverse effects of the disease.