Appendicitis and pelvic inflammatory disease are relatively common acute abdominal diseases in clinical practice, and there are the following differences between the two: First, the symptoms are different. Patients with appendicitis may have metastatic right lower abdominal pain in the early stage, and the early pain is mainly under the glabella and around the umbilicus, and the symptoms of abdominal pain may shift to the right lower abdomen after 6-8 hours. Patients with pelvic inflammatory disease start to have pain as soon as the pain is manifested as discomfort below the navel. The signs are different, appendicitis patients with the progress of the disease, will appear the right lower abdomen fixed pressure pain, rebound pain, and will not change with the change of time, pelvic inflammatory disease patients pain site mainly in the belly button below, once the rebound pain, often suggest that the pelvic infection is more serious. If the appendicitis is heavily infected, especially if it is accompanied by an embedded fecal stone, the appendix can be seen to be significantly enlarged and thickened through ultrasound or CT examination, with inflammatory exudate around it. In patients with pelvic inflammatory disease, after ultrasound and CT examination, more fluid in the pelvis can be seen, and the appendix does not show obvious inflammatory changes.