Possible causes: 1. Acute orchitis or epididymitis may cause stabbing pain in the testicles, usually accompanied by local swelling of the testicles or swelling of the epididymis, or changes such as redness of the scrotal skin, which requires ultrasound examination of the scrotum to further rule out. 2. 3.Stones in the ureter or bladder can cause radioactive pain in the testicular area, accompanied by symptoms such as back pain or frequent and urgent urination, and it is recommended that routine urinalysis and ultrasound of the urinary system and scrotum be performed to exclude them. 4.Spermatic varicose veins can cause unilateral pain and swelling in the testicle, and generally the scrotum will be palpated. The tortuous and thickened vascular tissue can be ruled out by ultrasound examination of the scrotum or the spermatic cord area.