Appendicitis can be triggered by obstruction of the appendiceal lumen, invasion of bacteria or gastrointestinal dysfunction. 1. The most common cause of appendiceal lumen obstruction is overgrowth of lymphoid follicles. The lumen of the appendix is small, narrow, and convoluted, making it susceptible to obstruction. Once obstruction occurs, the mucosa of the appendix will continue to secrete mucus, and the pressure in the lumen rises, causing obstruction of blood flow to the appendix. 2. Bacterial invasion often occurs in the case of appendiceal lumen obstruction, because the situation is easy for bacteria to survive and multiply, secretion of endotoxin damage to mucus epithelial cells to form ulcers, leading to the occurrence of infection. 3. Gastrointestinal dysfunction often triggers visceral nerve reflexes, leading to spasms of the muscles and blood vessels in the intestinal tract, and damage to the mucosal surface, which makes it easier for bacteria to invade the appendix and thus appendicitis occurs. If any of the above situations occurs, please consult a doctor in time for reasonable and standardized diagnosis and treatment.