Pain in the inner side of the ankle for no reason is usually not a big problem, the specific situation is that most cases of sudden pain in the inner side of the ankle may be osteoarthritis of the ankle joint, synovitis, rheumatoid arthritis of the ankle joint, etc., and is usually not a serious disease such as a tumor. Tumors and other diseases metastasize to the bones, usually in the epiphysis and spine, with the spine being the most common, and the patient will have symptoms of severe and persistent pain in the above areas, and there will be lesions at the primary site. The common causes of medial ankle pain for no reason are common diseases, which do not cause serious effects on the joints, and can be relieved soon or even cured completely after active treatment, so patients do not need to worry too much, and only need early treatment to get satisfactory relief.