High-altitude illness is a collective term for a cluster of acute clinical syndromes that directly consequence from rapid ascent to high altitude, viz., above 2500 m.  The acute syndromes affecting the brain include acute mountain sickness (AMS) and high-altitude cerebral edema (HACE). The current practice of high altitude medicine requires a deep knowledge of existing evidence. However, knowledge of the field is continuously evolving, and there are many gaps in the existing literature as well as areas of controversy despite existing research in the area. Each chapter begins with a real case from the author's clinical practice. After each case, a question is asked to allow the reader to reflect on clinical management before reading the answer and consolidating knowledge from experts in the field. They also focus on the standard practice of management and diagnosis, emphasizing evidence-based care when available as well as areas of uncertainty andactive debate in the medical literature. Written by experts in the field, High Altitude Medicine offers the most up-to-date knowledge about high altitude medicine that is not only useful for physicians at high altitude dedicated centers but also medical providers at different levels of their careers, especially emergency and urgent care physicians who are the ones that initially see the patient.