In general clinical practice, the pain associated with appendicitis mostly occurs in the lower right abdomen. Some patients experience very typical migratory right lower abdominal pain which usually starts in the upper abdomen, gradually moves around the navel, and finally localizes in the lower right abdomen. Direct pain in the lower right abdomen could also be indicative of appendicitis. In rare cases, if there is a reversal of organs or an abnormal position of the appendix, pain may occur in the upper right abdomen or lower abdomen as well. For pregnant women, the appendix may be positioned higher and could cause pain under the rib cage. Therefore, the diagnosis of appendicitis should be based on the specific condition of the patient and related diagnostic tests.