The second joint pain of index finger may be trauma, tenosynovitis, osteoarthritis, rheumatoid arthritis, osteoarthritis and so on. 1. Trauma: When patients have a history of trauma to the joints of the hand, interphalangeal joint injury occurs, which is also accompanied by damage to the surrounding muscles and ligaments, and then second joint pain of the index finger may occur. 2. Tenosynovitis: Some patients suffer from tenosynovitis, which may cause pain in the second joint of the index finger. 3. Rheumatoid arthritis: patients with this disease often have symmetrical and persistent arthralgia and swelling of the wrist, metacarpal fingers and proximal interphalangeal joints, which can lead to second joint pain of the index finger. 4. Osteoarthritis: the disease is more common in middle-aged and old women, the distal interphalangeal joints are most often involved, but also in the proximal interphalangeal joints and the first carpometacarpal joints, often appearing in the affected joints and their surrounding pressure and pain, stiffness, swelling, bony hypertrophy and dysfunction of the joints, which can be seen in the second joint pain of the index finger. There are many reasons for the second joint pain of the index finger, and it is recommended that the patient should consult a doctor in time, and under the guidance of the doctor, improve the examination to clarify the cause and standardize the treatment.