The Complexity of Diagnosing High-Altitude Pulmonary Edema: A Case Report and Review of the Differential Diagnosis of Greater Than Expected Hypoxemia at Altitude.

High-altitude pulmonary edema (HAPE) is a common presumptive diagnosis for a patient who experiences significant dyspnea and cyanosis at altitude. In this study, we present a case of a 58-year-old woman who was initially diagnosed with HAPE, although further evaluation revealed the presence of two underlying contributors to her significant hypoxemia at altitude. We discuss the medical workup for causes of greater than expected hypoxemia at altitude and the role some relevant medical comorbidities may play.