Acute appendicitis is usually a clinical acute abdomen with right lower abdominal pain as the main symptom. It often needs to be differentiated and diagnosed with urinary stones, right tubal pus, ileocecal tumors and other diseases. 1. Urologic stones: Usually, the right kidney stone or ureteral stone will cause right back pain, obvious percussion pain, which may be accompanied by right lower abdominal discomfort and right inguinal radiating pain. It is usually easily confused with acute appendicitis. The diagnosis can be made by ultrasonography. 2. Right tubal pus: generalized purulent tubal infection, which can lead to pressure pain and rebound pain in the right lower abdomen. Patients need to perform ultrasound to differentiate between it and acute appendicitis. 3. Ileocecal tumor: Usually, the cancer cells invade into the plasma membrane of the colon, causing perforation of the colon and right lower abdominal peritonitis. The patient should undergo abdominal CT to distinguish it from acute appendicitis. In addition, right adnexitis, torsion of ovarian cysts, ectopic pregnancy, and many other diseases can cause pain in the lower right abdomen, which can manifest as pain in the lower right abdomen and be easily misdiagnosed as appendicitis. Therefore, when pain in the lower right abdomen occurs, you should go to the hospital in time, complete the examination, make a clear diagnosis and then be treated accordingly.