Men who experience testicular pain are advised to go to the hospital for further examination to clarify the possible causes.1. Orchitis or epididymitis, there will be obvious testicular pain, the appearance of the testicle volume is obviously swollen, and there is an inflammatory reaction such as redness and swelling of the scrotal skin. Increased testicular volume or epididymal volume can be palpated on palpation. In the acute inflammatory stage, the boundary between testis and epididymis is not clear, and may be accompanied by exudation and testicular syringomyelia, which can be identified by ultrasound examination.2. Testicular tumor, the volume of testis increases progressively, accompanied by swelling and pain. The density of testicle increases when touching with hand, blood biochemical examination of testicular tumor and CT examination of testicle can be performed to identify whether there is tumor or not.3. Testicular torsion, which often occurs with acute pain. When touched by hand, the position of testicle is fixed, not easy to be pushed, with poor mobility, and accompanied by obvious swelling and pain. Ultrasound examination of testis and spermatic cord is needed to clarify whether there is torsion and ischemia.