The ankle is thick, the following reasons are common: First, ankle sprain or chronic ankle synovitis can lead to thickening of the ankle joint, local pressure will be softer, through active treatment, such as physical therapy, arthroscopic surgery, can make the ankle joint thickening phenomenon completely restored. Secondly, if the ankle joint thickening is caused by osteoarthritis of the ankle joint or osteoarthrosis, it is generally difficult to cure completely. Patients will show limited movement of the ankle joint, and there will be obvious friction sound when the joint moves, and there will be serious pain when walking with weight on the joint. X-rays usually show narrowing of the joint space, and MRI shows extensive damage to the articular cartilage, sometimes requiring joint fusion and joint replacement surgery.