Pain in the pinky joint can be caused by overwork, trauma, tendonitis, etc. 1. Overwork: If the pinky joint is worn out due to long hours of work, it can lead to problems such as hyperplasia and inflammation, which can lead to pain in the pinky joint. 2. Trauma: acute injury caused by strenuous exercise or external collision, etc., will cause damage to joints, muscles, ligaments, etc., which can be manifested as pain in the little finger; chronic injuries, such as long-term incorrect posture of the hand or sprains that are not handled in a timely manner, etc., will result in chronic joint injuries, leading to pain in the little finger joint. 3. Tendovaginitis: tendovaginitis of the tendon of the flexor tendon mainly caused by trauma, infection, cold and other factors. Finger flexor tendon tenosynovitis often occurs in the fingers, can lead to significant pain, popping or inability to straighten the little finger. Joint pain in the little finger can also be caused by synovitis, rheumatoid arthritis and gouty arthritis. If physiological causes are ruled out, you should consult a doctor to clarify the exact cause and, if necessary, treat accordingly.