There are several possible reasons for the simultaneous appearance of pain on the left side of the lower ribs and back pain: first, intercostal neuralgia, patients with intercostal neuralgia can experience pain at the intercostal nerve, which can lead to pain on the left side of the lower ribs and the back at the same time, which should be diagnosed by early examination and, if necessary, nerve nutrition and closure therapy; second, herpes zoster, which can appear in the early stages of herpes zoster. In the early stage of herpes zoster, there can be pain on the lower side of the rib cage and the back, then we have to observe the condition, and after 1-2 weeks of incubation period, there can be clusters of herpes, then we have to go to the dermatology department for diagnosis and treatment; thirdly, diseases of the thoracic spine, if there is a tumor or fracture of the thoracic spine, which compresses the nerve roots, there can also be pain on the lower side of the rib cage and the back, then we have to conduct nuclear magnetic and CT examinations of the thoracic spine for diagnosis and treatment. In this case, the diagnosis and treatment should be carried out by MRI and CT examination of the thoracic spine.