A rare pulmonary condition characterized by non-cardiogenic pulmonary edema occurring in otherwise healthy individuals within days of an ascent above 2500-3000 m. Early symptoms include exertional dyspnea, non-productive cough, chest tightness, and reduced exercise performance, followed by dyspnea at rest and possibly orthopnea, as well as gurgling in the chest and pink frothy sputum in advanced cases. Clinical signs are cyanosis, tachypnea, tachycardia, crackles or wheezing, and elevated body temperature (generally not exceeding 38.5°C). Signs of concomitant high-altitude cerebral edema may also be observed. Chest x-rays typically show patchy opacities predominantly in the right middle lobe.