In most cases, pain in the second joint of the middle finger is caused by muscle strain, tenosynovitis, arthrogryposis and other reasons. 1. Muscle strain: If the middle finger is subjected to prolonged exercise or extrusion, the local muscles are overworked and severely damaged, the muscle tissues and blood vessels are abnormally spasmodic, which involves the second joint, the pain in the second joint of the middle finger may occur. 2. Tendovaginitis: If the patient’s fingers have frequent activities for a long time, the tendons of the fingers are repeatedly rubbed in the tendon sheath, causing local edema phenomenon, if the middle finger has edema phenomenon, stimulating the local joints, which will cause the symptoms of pain in the second joint of the middle finger. 3. Arthrogryposis: If the patient has cysts in the second joint of the middle finger, with the enlargement of the cysts, the local nerves or blood vessels are compressed, resulting in abnormal local blood circulation, which will cause the symptoms of pain in the second joint of the middle finger. As there are many causes of pain in the second joint of the middle finger, it may also be caused by gout and osteoarthritis and other diseases. It is recommended to take standardized treatment as soon as possible to minimize the adverse effects of the disease.