Hypoxia.

Placebo and nocebo effects are particularly relevant in hypoxia research. Studies performed at high-altitude environments have shown that placebos can partially mimic the effects of oxygen (O2) and compensate for some of the imbalances at the level of critical life functions, such as ventilation, circulation, and even performance. In contrast, nocebos can exacerbate symptoms of hypoxia, suggesting how the brain can influence physiology even in conditions in which survival is at stake. Knowledge from research on placebo and nocebo effects at high altitudes may be incorporated into the treatment of respiratory diseases, for which psychologic aspects are no less important than physiological factors. Indeed, there is evidence that beliefs and expectations can influence responses to O2 deprivation in patients with respiratory diseases. Acknowledging the role of placebos and nocebos in natural hypoxic conditions can translate into a better management of hypoxic patients in medical settings and offer an opportunity to optimize O2 utilization strategies and enhance symptom management.