The swelling and pain of the back of the hand is considered to be caused by trauma, folliculitis, tenosynovitis and other reasons. 1. Trauma: If the hand is squeezed or collided in sports or work, resulting in local skin tissue damage, when infected by bacteria in the external environment, the back of the hand swelling and pain symptoms will occur. 2. Folliculitis: when the back of the hand is infected by Staphylococcus aureus causing red papules or papules centered on hazel, when the local skin secondary infection occurs, the back of the hand swelling and pain symptoms may occur. 3. Tenosynovitis: If the tendon activity is more frequent and long time exertion, resulting in local tissue inflammation, so that the blood circulation is abnormal, the back of the hand swelling and pain symptoms will occur. Because of the causes of the back of the hand swelling pain more reasons, it is recommended to go to the hospital in time for examination and diagnosis, to clarify the cause of the disease, under the guidance of professional physicians for targeted treatment.