Altitude-related illness occurs as a result of inadequate acclimatization. The mainstay of prevention is a slow, graded ascent profile which gives the body time to respond to a low-oxygen environment. The diagnosis of these conditions is often difficult in resource-limited environments, so history and a physical exam are key in identifying patients who will require descent and evacuation. Treatment modalities such as supplemental oxygen, portable hyperbaric chambers, and medications, are all temporizing measures until the patient can be safely evacuated to a lower elevation.