In normal people, the spleen is usually not palpable under the rib cage, but if it is palpable it indicates splenomegaly. There are many causes of splenomegaly, which can be differentiated into infectious and non-infectious factors. The former mainly includes acute and chronic infections causing splenomegaly, while non-infectious factors include bruising, blood disorders, connective tissue disease, reticuloendotheliosis, splenic tumours and splenic cysts.