This case study examines the interaction between the endocrine, cardiovascular and renal systems. The case narrative details Mr. Smith's high blood pressure that does not seem to respond to treatment. Although he takes good care of himself and follows a relatively healthy lifestyle and diet, his condition worsens with a new onset of acute symptoms. He is taken to the emergency room for further evaluation where he is eventually diagnosed with Conn's syndrome. This case would be of use in learning the renin-angiotensin-aldosterone system (RAAS) and the role of kidneys in fluid and electrolyte balance. In addition, the case is intended to help students understand the pathogenesis and treatment of hypertension, and the management of functional neoplasms. Although originally written for graduate level healthcare professional students, this case study may also be appropriate for teaching students in healthcare professional courses with prior baseline knowledge of clinical physiology and pharmacology.