1, the ankle sprain caused partial or complete tear of the medial and lateral collateral ligaments, but the treatment measures are not correct and timely enough, resulting in scar healing of the ligaments in a non-anatomical position, resulting in local microcirculation cannot be fully restored, resulting in long-term pain, which is the so-called “pain if it does not pass” in Chinese medicine. 2, after the ankle sprain, the synovial membrane or damaged ligament in the ankle joint gap, when the ankle joint activity can be repeatedly stimulated to these tissues and induce local inflammatory response, causing pain, and can be accompanied by swelling, and after the ankle joint rest stimulation eliminated, the inflammation subsided, so the symptoms can be relieved, so repeatedly. 3, the ankle sprain is followed by small fractures of the inner and outer ankle, because there was no x-ray examination or failed to find out, so the fracture was not treated in time and effectively, resulting in delayed healing, non-healing or deformed healing of the fracture, thus causing local pain. Therefore, ankle sprains should be taken seriously enough and it is best to seek medical attention in time. If the symptoms cannot be completely relieved in a short period of time, please seek help from a specialist.