Abstract
As altitude increases, atmospheric pressure and thus oxygen content decrease. This affects various physiological systems and triggers an acclimatisation process. Both acute responses and acclimatisation aim to ensure adequate oxygen delivery to the tissues. Respiratory rate and heart rate are elevated at altitude. The brain, which is particularly sensitive to oxygen deprivation, regulates cerebral blood flow to maintain oxygen supply. The body begins to produce more red blood cells, and the kidneys regulate water and acid-base balance. Metabolic rate increases, and carbohydrates are increasingly utilised as an energy source. Overall, these adaptations enable the body to function effectively despite the reduced oxygen availability at altitude.