Ankle sprains are a very common sports injury. Statistically, there are 302,000 ankle sprains per year in the United States. Medial ankle sprains alone resulting in ligament tears are extremely rare and are most often associated with ankle fractures or dislocations. The following is a description of the grading and treatment of acute external ankle injuries. Grade I: peroneal ligament strain, mild tear of the anterior talofibular ligament, and no tear of the posterior talofibular ligament or heel fibular ligament; the patient has mild to moderate swelling of the outer ankle, with a little petechiae, light pressure pain, normal mobility, and can walk with weight. Grade II: moderate injury with anterior talofibular ligament tear and partial heel-fibular ligament tear; the patient had local swelling, large petechiae, pressure pain and limited mobility. Grade 3: severe injury with tears of the anterior and posterior talofibular ligaments and the heel-fibular ligament and joint capsule. The patient has severe local swelling, extensive ecchymosis, significant pressure pain, and limited mobility. Treatment of acute ankle sprains: Functional rehabilitation is the mainstay of treatment for first- and second-degree injuries! Studies have shown that functional rehabilitation has fewer complications than cast immobilization of the ankle. Patients receive planned, regular exercise that allows for an early return to sports. Treatment for Grade III injuries includes external fixation in a cast, functional rehabilitation exercises, and surgical treatment. External immobilization in a plaster cast for >3 weeks is followed by functional exercise. Functional exercises: early external elastic immobilization, ice, and rest as much as possible. In the later stage: mobility exercises, strength exercises, proprioceptive exercises, and special activities. It is controversial whether to treat surgically in the acute phase. Some studies suggest that surgical treatment is better in restoring stability, but it can also bring related surgical complications.