http://en.wikipedia.org/wiki/Altitude_sickness
Altitude sickness
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Altitude sickness
Classification and external resources
ICD-10 T70.2
ICD-9 E902.0
DiseasesDB 8375 29615
eMedicine med/3225
MeSH D000532
Search Wiktionary Look up altitude sickness in Wiktionary, the free dictionary.
Altitude sickness, also known as acute mountain sickness (AMS), altitude illness, hypobaropathy, or soroche, is a pathological effect of high altitude on humans (and animals), caused by acute exposure to low partial pressure of oxygen at high altitude. It commonly occurs above
2,400 metres (approximately 8,000 feet).[1][2] Acute mountain sickness can progress to high altitude pulmonary edema (HAPE) or high altitude cerebral edema (HACE).[1][3]
The causes of altitude sickness are not fully understood.[1][4] The percentage of oxygen in air remains essentially constant with altitude at 21% up until 70,000 feet (21,330 m), but the air pressure (and therefore the number of oxygen molecules) drops as altitude increases — consequently, the available amount of oxygen to sustain mental and physical alertness decreases above 10,000 feet (3,050 m).[5][6] Altitude sickness usually does not affect persons traveling in aircraft because the cabin altitude in modern passenger aircraft is kept to 8,000 feet (2,440 m) or lower.
A superficially related condition is chronic mountain sickness, also known as Monge's disease, occurring only after prolonged exposure to high altitude.[7]
An unrelated condition, often confused with altitude sickness, is dehydration, due to the higher rate of water vapor lost from the lungs at higher altitudes.
Contents
[hide]
* 1 Introduction
* 2 Signs and symptoms
* 3 Severe cases
* 4 Prevention
o 4.1 Strenuous activity
o 4.2 Altitude acclimatization
o 4.3 Drugs
o 4.4 Oxygen enrichment
o 4.5 Other methods
* 5 Treatment
* 6 See also
* 7 References
* 8 External links
[edit] Introduction
High altitude or mountain sickness is defined as a collection of nonspecific symptoms that can resemble a case of flu, carbon monoxide poisoning or a hangover caused by high altitudes[8]. It is hard to determine who will be affected by altitude-sickness, as there are no specific factors that compare with this susceptibility to altitude sickness. However, most people can climb up to 2500 meters (8000 ft) normally.
Generally, different people have different susceptibilities to altitude sickness. For some otherwise healthy people, Acute Mountain Sickness (AMS) can begin to appear at around 2000 meters (6,500 ft) above sea level, such as at many mountain ski resorts, equivalent to a pressure of 80 kPa. AMS is the most frequent type of altitude sickness encountered. Symptoms often manifest themselves six to ten hours after ascent and generally subside in one to two days, but they occasionally develop into the more serious conditions. Symptoms include headache, fatigue, stomach illness, dizziness, and sleep disturbance. Exertion aggravates the symptoms.
High altitude pulmonary edema (HAPE) and cerebral edema (HACE) are the most ominous of these symptoms, while AMS, retinal hemorrhage, and peripheral edema are less severe forms of the disease. The rate of ascent, altitude attained, amount of physical activity at high altitude, as well as individual susceptibility, are contributing factors to the onset and severity of high-altitude illness.
Altitude sickness usually occurs following a rapid ascent and can usually be prevented by ascending slowly.[9] In most of these cases, the symptoms are temporary and usually abate as altitude acclimatisation occurs. However, in extreme cases, altitude sickness can be fatal.
The word "soroche" came from South America and originally meant "ore", because of an old, incorrect belief that it was caused by toxic emanations of ores in the Andes mountains. [1]
[edit] Signs and symptoms
This sign near the peak of Mount Evans (elev. 14264 ft or 4,350 meters) in Colorado, USA, warns of altitude sickness symptoms.
Headaches are a primary symptom used to diagnose altitude sickness, although a headache is also a symptom of dehydration. A headache occurring at an altitude above 2,400 meters (8000 feet = 76 kPa), combined with any one or more of the following symptoms, can indicate altitude sickness:
* Lack of appetite, nausea, or vomiting
* Fatigue or weakness
* Dizziness or light-headedness
* Insomnia
* Pins and needles
* Shortness of breath upon exertion
* Persistent rapid pulse
* Drowsiness
* General malaise
* Peripheral edema (swelling of hands, feet, and face).
Symptoms that may indicate life-threatening altitude sickness include:
* pulmonary edema (fluid in the lungs):
o persistent dry cough
o fever
o shortness of breath even when resting
* cerebral edema (swelling of the brain):
o headache that does not respond to analgesics
o unsteady gait
o increased vomiting
o gradual loss of consciousness.
Bogoda 2,640 M above sea level is the most ever for a bidding city and above the dangerous 2,400 M level for altitude sickness.