The second joint of the index finger is painful when bending, considering tenosynovitis, osteoarthritis, joint injury, gout, according to the cause of the disease to take medication, physical therapy, surgical treatment. 1. Tenosynovitis: the second joint of the index finger is painful when bending, and some of them may have popping or jamming, which can be treated with hot compresses, closed injections, and tenosynovial release surgery if the conservative treatment is invalid. 2. Osteoarthritis: joint hyperplasia and degeneration, serious deformation of the joints, you can take oral glucosamine sulfate capsules and aceclofenac tablets under the guidance of a doctor, ultrasound physiotherapy or infrared physiotherapy. 3. Joint injury: If there is fracture in the radiograph, finger splinting is needed; if there is no fracture, ligament injury is considered, and braking and rest are taken; if the joint is unstable, ligament repair surgery is needed. 4. Gout: sudden joint pain, accompanied by redness and swelling, you can take colchicine orally under the guidance of a doctor, and use diclofenac diethylamide cream externally. Therefore, the second joint of the index finger hurts when it bends and you need to go to the hospital to check and clarify the cause of the disease for treatment.