We present a case of extreme bradycardia in an 18-year-old man, accompanied by bilateral pleural effusions, pericardial effusion, endocrine dysregulation and Horner's syndrome. Despite extensive investigations as an inpatient and multidisciplinary input, it was not until subsequent assessment by an endocrine team that it was revealed that his presentation was attributable to an eating disorder. Following dietary advice, easing of extreme exercise and continued support, the patient improved in all parameters including body mass index and he remains well. This case demonstrates the importance of a thorough personal history incorporating all aspects of social and dietary history.