###Human: What could be the reason for stinging pain of left scrotum? ###Assistant: Hello. I can understand your concern. If there is any history of injury to scrotum then most likely it is a hematoma or infection post trauma. The pain could occur because of pressure over testis by tight underpants. This sometimes results in a picture similar to an infection. I would advise you to get USG scrotum done. This will rule out any hematoma or infection. A urine analysis should be done to rule out the cause. Please provide the reports for further assistance. Thanks and take care.