Atelectasis development of atelectasis include: type of surgery (thoracic, cardiopulmonary surgeries), use of muscle relaxation, obesity, high oxygen, the lower lung segments. Factors not associated with the development of atelectasis include: age, presence of COPD or asthma, and type of anesthetic. In the early 1950s, in UK aviation medicine, the condition "acceleration atelectasis" was given the name "Hunter Lung" due to its prevalence in pilots of the transonic fighter jet the Hawker Hunter, which used a 100% oxygen schedule. Clinically significant atelectasis is generally visible on chest X-ray; findings can include lung opacification and/or loss of lung volume. Post-surgical atelectasis will
High-altitude adaptation in humans Tibetans, Andeans and Ethiopians is indeed an observable instance of the process of natural selection in acting on favourable characters such as enhanced respiratory mechanisms in humans. Humans are naturally adapted to lowland environment where oxygen is abundant. When people from the general lowlands go to altitudes above , with atmospheric pressure 74% of normal they experience mountain sickness, which is a type of hypoxia, a clinical syndrome of severe lack of oxygen. Complications include fatigue, dizziness, breathlessness, headaches, insomnia, malaise, nausea, vomiting, body pain, loss of appetite, ear-ringing, blistering and purpling of the hands and feet, and dilated veins.