From mountain to bedside: understanding the clinical relevance of human acclimatisation to high-altitude hypoxia.

For centuries man has strived to reach the greatest heights on earth. In order to explain the physiological changes that are needed to achieve this, physiologists have tended to focus on the improvements made in oxygen delivery to the body's tissues. Although this explains much of the acclimatisation process, it has not been able to address the large interindividual variations seen in human performance at altitude. In recent years, attention has shifted and now focuses on microvascular and cellular responses in an attempt to explain these differences. Investigating these processes not only helps to unravel the process of acclimatising to altitude, but it may also improve our understanding of the body's response to hypoxia in those with critical illness.