Men who hold their urine at night, a little cramp on the left side after urinating in the morning, if there are no other uncomfortable symptoms, just a transient pain, most of them belong to the normal phenomenon. Holding back urine at night will cause the bladder to fill up, may pull the local nerve, so there is a little bit of pain after urinating on the left side of the symptom, just a transient pain, there is no frequent urination, urinary urgency, urinary difficulties and persistent pain and other symptoms, also belong to the normal physiological phenomenon, do not need to worry about and treatment. Normally, you should pay attention to personal hygiene, drink more water, urinate regularly, empty the bladder before going to bed, avoid holding urine. If the pain persists, or there are symptoms such as frequent urination, urinary urgency, unclean urination, etc., it is necessary to go to the hospital for further examination to see if there is any substantial disease of the urinary organs.