Redness of the male scrotum is recommended to go to the hospital for further examination to clarify the possible causes. 1. It may be cellulitis of the scrotal skin, which can cause redness of the scrotal skin, accompanied by increased skin temperature and local pain, and may also be accompanied by local skin erosion and increased secretion, all of which are caused by bacterial infection and need further bacteriological examination to clarify. 2. If there is inflammation of scrotal contents, such as orchitis, epididymitis, etc., it can cause redness of scrotal skin, accompanied by skin swelling or increased skin temperature, local pain, etc., and can be accompanied by swelling and pain of testicles and epididymis, which requires ultrasound examination of scrotal contents. 4. Local skin allergy can also cause redness of the skin, usually accompanied by itching or a history of exposure to scrotal allergens, and further allergen testing is needed to confirm the diagnosis.