<Tr> <Th> Specialty </Th> <Td> Emergency medicine </Td> </Tr> <P> Altitude sickness, also known as acute mountain sickness (AMS), is a negative health effect of high altitude, caused by acute exposure to low amounts of oxygen at high altitude . 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". </P> <P> Although minor symptoms such as breathlessness may occur at altitudes of 1,500 metres (5,000 ft), AMS typically only occurs above 2,400 metres (8,000 ft). It is hard to determine who will be affected by altitude sickness . Diagnosis is supported in those who have a moderate to severe reduction in activities . </P> <P> Acute mountain sickness can progress to high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE), both of which are potentially fatal, and can only be cured by immediate descent to lower altitude or oxygen administration . Chronic mountain sickness is a different condition that only occurs after long term exposure to high altitude . </P>

When do you start feeling the effects of altitude
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