There are several possible causes of pain below the left back scapula: 1. intercostal neuralgia, intercostal neuralgia can appear as pain in the back where the intercostal nerve travels, often radiating pain or pinprick-like pain. 2. herpes zoster, in the early stages of herpes zoster, can appear as pain in the back, can also appear as pain below the back scapula, after 1-2 weeks of incubation period, can appear in clusters of herpes. 3, rib diseases, when there is a tumor in the ribs, there can also be pain in the left back under the scapula, then the relevant examination and CT examination for diagnosis. 4, gallbladder diseases, when there is cholecystitis or gallbladder stones, there can also be pain in the back under the scapula, then the ultrasound and CT examination of the gallbladder for diagnosis. In this case, ultrasound and CT examination of the gallbladder should be performed for diagnosis.