What is "altitude sickness"

n. (context medicine English) A pathological condition caused by oxygen deficiency at high altitudes; symptoms include shortness of breath, nausea, and nosebleed.

n. effects (as nosebleed or nausea) of oxygen deficiency in the blood and tissues at high altitudes

Altitude sickness—also known as acute mountain sickness (AMS), is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude. Although minor symptoms such as breathlessness may occur at altitudes of , AMS commonly occurs above . 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 without difficulty.

Acute mountain sickness can progress to high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE), which are potentially fatal.

Chronic mountain sickness, also known as Monge's disease, is a different condition that only occurs after very prolonged exposure to high altitude.