Hidden pain under the left rib cage may be a condition such as costochondritis and shingles. 1. costochondritis. Costochondritis is an inflammatory reaction between the contact surface of ribs and cartilage, which is aseptic inflammation. The main manifestation is localized pain in the junction area of the ribs and the sternum, and it is more common in young and strong women. Most of the symptomatic treatment, the prognosis is good. 2. Herpes zoster. Herpes zoster is because the patient is infected by varicella zoster virus, belonging to an acute skin and mucous membrane infectious diseases, often characterized by sudden unilateral distribution along the nerve zones, dense groups of herpes, severe pain. In the early stages, it will manifest as a vague pain, which can be cured by antiviral and pain-relieving treatments. Hidden pain under the left rib cage may also have heart disease, stomach disease and so on. You should go to the hospital in time, ask the doctor to clarify the cause of the disease, and if necessary, carry out appropriate treatment.