Anorexia (eriving from the Greek "α(ν)-" (a(n)-, a prefix that denotes absence) + "όρεξη (orexe) = appetite) is the decreased sensation of appetite. While the term in non-scientific publications is often used interchangeably with one of its causes, anorexia nervosa, there are many possible causes for a decreased appetite, some of which may be harmless while others pose significant risk for the person.