Altitude sickness—also known as
acute mountain sickness (
AMS),
altitude illness,
hypobaropathy,
"the altitude bends", or
soroche—is a pathological
effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at
high altitude. It commonly occurs above 2,400 metres (8,000 feet). It presents as a collection of
nonspecific symptoms, acquired at high altitude or in low air pressure, resembling a case of "flu, carbon monoxide poisoning, or a hangover". It is hard to determine who will be affected by altitude sickness, as there are no specific factors that correlate with a susceptibility to altitude sickness. However, most people can ascend to 2,400 metres (8,000 ft) without difficulty.