The Alvarado score is a clinical scoring system used to assess the likelihood of acute appendicitis based on symptoms, physical signs, and laboratory findings. It includes eight criteria remembered by the mnemonic MANTRELS: migration of pain to the right lower quadrant, anorexia, nausea or vomiting, tenderness in the right lower quadrant, rebound tenderness, elevated temperature, leukocytosis, and shift of white blood cells to the left. Tenderness in the right lower quadrant and leukocytosis are