Constant swelling and pain below the left rib cage is related to lung diseases, pleural effusion, pancreatic diseases, etc. If the left side of the rib cage is often swollen and uncomfortable, it is mainly considered to be caused by lung diseases. Pneumonia is mainly caused by viruses, fungi, parasites, bacteria and other factors of infection, the patient mainly manifested as respiratory or systemic symptoms, especially in coughing or coughing up sputum will lead to the left side of the ribcage area of the pain aggravated, some patients will also appear localized distension and pain performance. If the left side of the chest cavity of the patient appears obvious pain, chest tightness, pain symptoms after activity, can also be considered to be caused by pleural effusion, should be promptly to the hospital for examination. In addition, diseases or inflammation in the spleen or pancreas, which cause local nerve invasion, can also lead to localized distension and pain, which can be clearly diagnosed by ultrasound or CT examination of the upper abdomen.