Virtually all body systems can contribute to voice function and dysfunction. An appropriate history includes not just all aspects of voice use (professional and non-professional), smoking, occupation, allergies and other obvious factors. Other systems that may cause or contribute to voice disorders also must be assessed including gastroenterological (especially reflux), endocrinological (hormones), respiratory (asthma, chronic obstructive pulmonary disease and others), musculoskeletal and other systems. An understanding of the function of the entire body is needed in order to diagnose and treat voice disorders correctly. Physical examination should be comprehensive, and appropriate tests should be obtained.