Rapidly Progressing Fatal High-Altitude Illness in a Patient with Hyperthyroidism

High-altitude illness (HAI) refers to a broad spectrum of diseases ranging from acute mountain sickness to high-altitude cerebral and pulmonary edema that are induced by high-altitude hypoxic stress. In this study, we present a case of a rapidly progressing fatal HAI (high-altitude cerebral edema and pulmonary edema) in a patient with hyperthyroidism. The victim is a 20-year-old female being treated for Graves' disease, who died after visiting a high-altitude region for travel. The autopsy examination showed cerebral and pulmonary edema, and right ventricular enlargement. A postmortem thyroid function test revealed thyrotoxic status; thyrotoxicosis may have contributed to the rapid progression of the HAI.