The organs below the left rib cage generally refer to the body to the left of the midline and include the left lung, heart, spleen, part of the stomach, the splenic flexure of the transverse colon, part of the small intestine, and the adrenal glands. If discomfort occurs below the left side of the ribs, it is important to consider that there may be a lesion in one of these organs, such as infarction of the spleen, torsion of the spleen, inflammation or tumor in the tail of the pancreas, fluid retention in the left side of the kidneys, pleurisy on the left side, or lobar pneumonia in the left lower lung. Clinical diagnosis of the disease is closely related to the anatomical structure of the body, and the combination of anatomical structure, symptoms and signs is helpful in the analysis of the disease. If pain, swelling or other discomfort occurs, it is necessary to consult a doctor in time and do relevant examinations to clarify the specific lesions and carry out treatment.