Causes of pain around the back of the testicles include orchitis, varicocele, etc. Treatments include medications such as antibiotics and surgery. 1. Testiculitis: Testiculitis is a disease in which the testicles or epididymis are infected by pathogens, and common causative agents include E. coli and so on. The main symptoms are painful enlargement of the scrotal contents on one side, syringomyelia, testicular atrophy and so on. Treatment includes medication such as ceftriaxone, levofloxacin, etc. If the condition is serious, it can be treated by surgery such as drainage, decompression and excision. 2. Varicocele: Varicocele refers to abnormal expansion and tortuosity of the veins of the spermatic cord and impaired blood return. The main clinical symptoms are enlargement of the scrotum on the affected side accompanied by a feeling of swelling, which is aggravated by standing up and alleviated by lying down. Treatment includes medication, such as indomethacin, and surgery, such as high ligation of the spermatic vein, if the condition is serious. When patients experience discomfort, they should go to the hospital immediately and choose the appropriate treatment plan under the guidance of the doctor.