Sleep disorders at high altitude are common and well-known for centuries. One symptom of the complex is periodic breathing (PB). PB occurs from a disbalance of the negative feedback loop of ventilation control, and at high altitude, it is increased by a phase shift of 180 degrees between hyperventilation and hypoxia. This paper explains the mechanisms that trigger the problem and discusses whether PB may be of advantage or disadvantage for the person going to high altitude. Up to about 3,000-3,500 m, PB may be of advantage because it stabilizes oxygen saturation at a relatively high level. At higher altitudes, disadvantages predominate because frequent arousals cause total sleep deprivation and mental and physical impairment of the victim. Correct acclimatization and "defensive" altitude profiles are gold standard, which minimize PB and optimizes recreative sleep, although they cannot mask PB completely, especially at extreme altitude.