[Sleep at Altitude]

Advancing infrastructure of mountain regions allows not only well-prepared mountaineers, but also elderly people with pre-existing illness the stay at high altitudes. Based on the hypoxic conditions, low oxygen saturation values are reached, which cause severe hypoxemia in the tissue. Symptoms of acute mountain sickness appear even at moderate altitude, which are manifested during sleep. Patients suffering from sleep apnea are at high risk, because of the obstructive ventilation disorder in combination with less oxygen availability. Concurrently, gender differences play a decisive role. Due to the respiratory stabilizing impact of estrogen, women are faster in adapting to altitude differences. A reduction of sleep duration and extended wake phases are shown, which causes lower sleep sufficiency. With continued rise of altitude, the arousal-index increases. For individual differences concerning altitude induced problems, individual acclimatization protocols are needed. Well prepared pre-acclimatization could prevent altitude induced sleep problems, as well as the treatment of such.