The common causes of swollen and painful finger joints at night are poor sleeping posture, osteoarthritis, rheumatoid arthritis and so on. 1. Poor sleeping posture: poor sleeping posture, compression of the finger joints, resulting in poor blood circulation, venous stasis, return obstacles, joint swelling and pain will occur, after the activities of the blood flow back to normal, swelling and pain symptoms gradually disappear. 2. Osteoarthritis: Osteoarthritis will appear in the early stage of joint pain, slight swelling, swelling and pain can disappear after activities, it is not easy to be detected, so there will be a finger joint swelling and pain in the night after activities disappear. 3. Rheumatoid arthritis: is a synovitis as the main lesion of autoimmune diseases, will also appear joint stiffness, swelling, after activities to reduce the symptoms. There are other causes of finger joint swelling and pain at night, such as gout, etc. It is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.