A method and apparatus for diagnosing a user's health state are provided. The apparatus includes including a voice detecting unit which detects and monitors a user's voice; a voice analyzing unit which extracts a voice feature from a voice detected by the voice detecting unit, based on a health state to be diagnosed; a voice diagnosing unit which diagnoses a health state of the user by comparing the voice feature extracted by the voice analyzing unit with an abnormal state reference, and which monitors a change in the health state; and a diagnosis outputting unit which outputs information regarding the health state and a health state change diagnosed by the voice diagnosing unit.