1, abdominal pain The typical acute appendicitis initially has pain in the upper middle abdomen or around the umbilicus, and after a few hours the abdominal pain shifts and is fixed in the right lower abdomen. The early stage is a kind of visceral nerve reflex pain, so the pain in the middle and upper abdomen and around the umbilicus is more diffuse and often cannot be located exactly. When the inflammation spreads to the plasma membrane layer and the wall peritoneum, the pain becomes fixed in the right lower abdomen, and the original mid-upper abdominal or periumbilical pain is reduced or disappears. Therefore, the absence of a typical history of metastatic right lower abdominal pain does not exclude acute appendicitis. Simple appendicitis often presents with paroxysmal or persistent distension and dull pain, and persistent severe pain is often indicative of septic or gangrenous appendicitis. Persistent severe pain extending to the mid-lower abdomen or both lower abdomens is often a sign of perforated gangrene of the appendix. Sometimes the abdominal pain is relieved by perforated appendiceal gangrene, but this pain relief is temporary and other accompanying symptoms and signs do not improve or even increase. 2. Gastrointestinal symptoms The gastrointestinal symptoms of simple appendicitis are not prominent. In the early stage, there may be nausea and vomiting due to reflex gastric cramps. In pelvic appendicitis or appendiceal gangrene perforation, there may be an increase in the number of bowel movements. 3, fever Generally only low fever, no chills, septic appendicitis usually does not exceed 38 ℃. High fever is usually seen in appendiceal gangrene, perforation or peritonitis. The presence of chills and jaundice suggests a possible complication of purulent portal phlebitis. 4, pressure pain and rebound pain Abdominal pressure pain is a manifestation of inflammatory stimulation of the wall peritoneum. The appendiceal pressure pain point is usually located at the McKay’s point, which is the junction of the middle and outer 1/3 of the line between the right anterior superior iliac spine and umbilicus. The pressure point may change with the anatomical location of the appendix, but the key is a fixed pressure point in the right lower abdomen. Rebound pain is also known as Blumberg’s sign. In patients with obesity or posterior appendicitis of the appendix, the pressure pain may be mild, but there is significant rebound pain. 5, abdominal muscle tension Appendiceal suppuration is this sign, gangrene perforation complicating peritonitis when the abdominal muscle tension is particularly significant. But older or obese patients with weaker abdominal muscles, must also check the contralateral abdominal muscles for comparison, in order to determine the presence of abdominal muscle tension. 6, skin sensory hypersensitivity In the early stage, especially in the appendiceal cavity when there is obstruction, the right lower abdominal skin sensory hypersensitivity phenomenon can occur, the range is equivalent to the 10th to 12th thoracic medullary segmental innervation area, located in the highest point of the right iliac crest, the right pubic crest and umbilicus constitutes the triangle, also known as Sherren’s triangle, it does not change due to the different location of the appendix, such as appendiceal gangrene perforation is in this triangle of skin sensory hypersensitivity phenomenon that If the appendix is perforated, the skin sensory allergy in this triangle disappears.