Appendicitis begins with luminal obstruction (fecalith 40%, lymphoid hyperplasia 60%) leading to mucus accumulation, bacterial overgrowth, and increased intraluminal pressure. Venous congestion progresses to arterial compromise, causing transmural ischemia and necrosis. Perforation occurs in 20-30% of cases, typically within 36-72 hours of symptom onset, leading to localized abscess or diffuse peritonitis. The nurse must perform serial abdominal assessments, manage perioperative care, administer antibiotics and analgesics per protocol, and monitor for post-operative complications including abscess, wound infection, and ileus.