Altitude Sickness Prognosis The prognosis for acute altitude sickness is great as long as common sense is used . Descending, delaying further ascent, rest, and paying attention to the body`s symptoms are usually all that is necessary to ensure a complete recovery. Thin air pulmonary edema includes a good outcome if symptoms are regarded and treated early. If descent is definitely impossible or if hyperbaric therapy, supplemental oxygen, and access to medical care are not available, HAPE can progress to respiratory failure and to death ultimately. Remember that HAPE is the true number one reason behind death from thin air illness.