A vague pain in the left testicle may be caused by epididymitis, or it may be caused by orchitis. When this clinical symptom appears, it is recommended to go to the hospital in time to do relevant examinations to clarify the diagnosis, which can be done by scrotal ultrasound and physical examination. Once the diagnosis of epididymitis is confirmed, broad-spectrum anti-inflammatory drugs such as cefprozil, cefoxitin, cephalexin, cefamandole, etc. can be administered intravenously for treatment, and then changed to oral anti-inflammatory drugs for treatment after the symptoms improve. It is recommended to pay attention to rest and wear scrotal brace underwear to hold up the scrotum.