The Hamburger sign is used in the diagnosis of appendicitis. The sign is used to rule out that disease, with the physician inquiring if the patient would like to consume his/her favourite food. If a patient wants to eat, consider a diagnosis other than appendicitis. Anorexia is 80% sensitive for appendicitis. A positive hamburger sign is demonstrated by a patient declining food.
References
Hamburger sign Wikipedia(Text) CC BY-SA