There are several causes of pain below the left rib cage in men: first, costochondritis, below the rib cage is the rib arch made up of rib cartilage, when inflammation of the rib cage and cartilage occurs, there will be pain due to costochondritis. Second, the early stages of herpes zoster, in the early stages of herpes zoster will appear pain in the intercostal nerve distribution area, can also be manifested as pain below the rib cage, this time to observe whether there are clusters of herpes appear, if there is herpes appear must go to the dermatology department for consultation and treatment. Third, intercostal neuralgia, intercostal neuralgia can also appear as pain below the rib cage, it is often a pinprick-like pain in the nerve distribution area. Fourth, intestinal diseases, such as enteritis or intestinal tumors, can also appear deep pain below the rib cage, which should be further diagnosed by a colonoscopy.