High altitude pulmonary edema is a life-threatening condition that remains a concern for climbers and clinicians alike. It is defined as a non-cardiac pulmonary edema occurring at altitudes exceeding 3000m in non-acclimatised individuals. Within the last decade, studies have shown ultrasonography to be valuable in the accurate diagnosis of a variety of lung pathologies, including cardiogenic pulmonary edema, pleural effusion, pneumothorax, and lung consolidation. Recently, studies conducted in remote areas have demonstrated that ultrasound lung comets (B lines) can be used as a measure of sub-acute pulmonary edema and high altitude pulmonary edema in climbers ascending to altitude. These studies also demonstrated that small portable ultrasound devices are reliable at high altitude in a cold and hypobaric environment.