Acute appendicitis is a common cause of abdominal pain, typically affecting individuals aged 5–40. It results from luminal obstruction, often by a fecolith or lymphoid hyperplasia, leading to inflammation. Classic symptoms include right iliac fossa pain, nausea, vomiting, and fever, but presentations may vary, especially in children, elderly, or pregnant women. Diagnosis is primarily clinical, supported by blood tests, urinalysis, and imaging (ultrasound or CT). Management includes admission, IV fluids, antibiotics, and appendicectomy—preferably laparoscopic. Complications include perforation, abscess, and peritonitis. Follow-up includes rest, wound care, and monitoring for recurrence or rare complications like stump appendicitis.