Altitude sickness, also known as acute mountain sickness (AMS) or altitude illness is a pathological condition that is caused by lack of adaptation to high altitudes. It commonly occurs above 2,440 metres (8,000 feet). If untreated, the condition can result in death. High altitude are regions on the Earths surface (or in its atmosphere) that are high above mean sea level. ...

Introduction

Different people have different susceptibilities to altitude sickness. For some otherwise healthy people symptoms can begin to appear at around 1,500 meters (5,000 feet) above sea level. This is the altitude of Mexico City (2,240m.-7,349ft.) and Denver, Colorado (1,609m.-5,280ft). Diets high in carbohydrates may make people suffering AMS feel better. The carbohydrates seem to liberate more energy and oxygen compared to their lipid counterparts. Jump to: navigation, search Mexico City (Spanish: Ciudad de México) is the name of a megacity located in the Valley of Mexico (Valle de México), a large valley in the high plateaus (altiplano) at the center of Mexico, about 2,240 metres (7,349 feet) above sea-level... Jump to: navigation, search Denver skyline, 1999. ... Jump to: navigation, search Carbohydrates (literally hydrates of carbon) are chemical compounds that consist of monosaccharide sugars of varying chain lengths and that have the general chemical formula Cm(H2O)n or are derivatives of such. ...

Signs and symptoms

Headache is a primary symptom used to diagnose altitude sickness. A headache occurring at an altitude above 8000 feet, combined with any one of the following symptoms, indicates probable altitude sickness. A headache (medically known as cephalalgia) is a condition of mild to severe pain in the head; sometimes upper back or neck pain may also be interpreted as a headache. ...

• Anorexia (loss of appetite), nausea, or vomiting
• Fatigue or weakness
• Dizziness or light-headedness
• Insomnia

The early symptoms of altitude sickness include drowsiness, general malaise, and weakness, especially during physical exertion. More severe symptoms are headache, insomnia, persistent rapid pulse, nausea and sometimes vomiting, especially in children. Extreme symptoms include confusion, psychosis, hallucination, symptoms resulting from pulmonary edema (fluid in the lungs) such as persistent coughing, and finally seizures, coma and death. Jump to: navigation, search Anorexia (deriving from the Greek όρεξη (orexe) = appetite) is the decreased sensation of appetite. ... Nausea (Greek Ναυτεία) is the sensation of unease and discomfort in the stomach with an urge to vomit. ... Fatigue may refer to: Fatigue (physical) - tiredness in humans Fatigue (material) - failure by repeated stress in materials Fatigues (uniform) - military uniform (BDU or ACU) Chronic Fatigue Syndrome - a medical condition Battle fatigue - also known as Post-traumatic stress disorder Readers fatigue - a side-effect of parsing poorly formatted textual... Dizziness (Latin: Vertigo) is the sensation of instability. ... Jump to: navigation, search Light-headedness is a common and often unpleasant sensation of dizziness and/or feeling that one may be about to faint, which may be transient, recurrent, or occasionally chronic. ... Jump to: navigation, search For the novel by Stephen King, see Insomnia (novel); for the Norwegian movie and its American remake, see Insomnia (movie). ... Malaise is a term used to refer to a general state of discomfort, tiredness, or illness. ... Pulmonary edema is swelling and/or fluid accumulation in the lungs. ... Seizures (or convulsions) are temporary alterations in brain function expressing themselves into a changed mental state, tonic or clonic movements and various other symptoms. ... This article is in need of attention from an expert on the subject. ...

Severe cases

The most serious symptoms of altitude sickness are due to edema (fluid accumulation in the tissues of the body). At very high altitude, humans can get either high-altitude pulmonary edema (HAPE), or high altitude cerebral edema (HACE). These syndromes are potentially fatal. The physiological cause of altitude-induced edema is not conclusively established. For those suffering HAPE or HACE, dexamethasone may provide temporary relief from symptoms in order to keep descending under their own power. Jump to: navigation, search Edema (BE: oedema, formerly known as dropsy) is swelling of any organ or tissue due to accumulation of excess fluid. ... Pulmonary edema is swelling and/or fluid accumulation in the lungs. ... This page describes terms and jargon related to climbing and mountaineering. ... Jump to: navigation, search Cerebral edema is swelling of the brain which can occur as the result of a head injury, cardiac arrest or from the lack of proper altitude acclimatization. ... This page describes terms and jargon related to climbing and mountaineering. ... Jump to: navigation, search Dexamethasone is a synthetic member of the glucocorticoid class of hormones. ...

HAPE occurs in ~2% of those who are adjusting to altitudes of ~3000 m (10,000 feet) or more. It can be life threatening. Symptoms include fatigue, dyspnea, headache, nausea, dry cough without phlegm, pulmonary edema, fluid retention in kidneys, and rales. Descent to lower altitudes alleviates the symptoms of HAPE. Dyspnea (Latin dyspnoea, Greek dyspnoia from dyspnoos - short of breath) or shortness of breath (SOB) is perceived difficulty breathing or pain on breathing. ... Jump to: navigation, search Edema (BE: oedema, formerly known as dropsy) is swelling of any organ or tissue due to accumulation of excess fluid. ... The symptoms of rales are wheezy and raspy sounds originating from a compromise in the respiratory tract. ...

HACE is a life threatening condition that can lead to coma or death. It occurs in about 1% of people adjusting to altitudes above ~2700 m (9,000 feet). Symptoms include headache, fatigue, visual impairment, bladder dysfunction, bowel dysfunction, loss of coordination, paralysis on one side of the body, confusion, and slowed reflex response. Descent to lower altitudes may save those afflicted with HACE.

Altitude acclimatization

Altitude acclimatization is the process of adjusting to decreasing oxygen levels at higher elevations, in order to avoid altitude sickness. Once above approximately 3,000 metres (10,000 feet), most climbers and high altitude trekkers follow the "golden rule" - Trek/Climb High, Sleep Low. For high altitude climbers, the way to acclimatise is to stay a few days at base camp, climb up to a higher camp (slowly), stay there for one night initially, then return to base camp. This process is then repeated a few times, each time extending the time spent at higher altitudes to let the body "get used" to the oxygen level there. Once the climber is used to that altitude, the process is repeated with a camp placed at higher elevations. The general rule of thumb is to not ascend more than 300 metres (1,000 feet) per day to sleep. That is, one can climb from 3,000 (10,000 feet) to 4,500 metres (15,000 feet) in one day, but one should then descend back to 3,300 metres (11,000 feet) to sleep. This process cannot be rushed, and this explains why climbers need to spend days (or even weeks at times) acclimatising before attempting to climb a high peak. Jump to: navigation, search General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... In climbing, a base camp may be set up to provide the starting point for a multiple day or week assault on climbing a mountain. ...

Acetazolamide may help some people in speeding up the acclimatization process and can treat mild cases of altitude sickness. Drinking plenty of water will also help in acclimatization to replace the fluids lost through the heavier breathing. Patients can sometimes control mild altitude sickness by consciously taking ten to twelve rapid large breaths every five minutes. If overdone, this can blowoff too much carbon dioxide and cause tingling in the extremities of the body. Other treatments include injectable steroids to reduce pulmonary edema, and inflatable pressure vessels to relieve and evacuate severe mountain-sick persons. Acetazolamide, sold under the trade name Diamox®, is a carbonic anhydrase inhibitor that is used to treat glaucoma, epileptic seizures, benign intracranial hypertension and altitude sickness. ...

The only real cure once symptoms appear is to take the sufferer to a lower altitude. For serious cases of AMS, a Gamow bag can be used to reduce the effective altitude by as much at 1,500 meters (5,000 feet). A Gamow bag is a portable plastic pressure bag inflated with a foot pump. A gamow bag is an inflatable pressure bag that is large enough to fit a person inside. ...

See also

• Mountain climbing

Mountaineering is an umbrella term that can variously be used to describe the actions of climbing, hillwalking and scrambling. ...

External links

• Merck Manual entry on altitude sickness
• University of Buffalo Reporter article on research into the cause of altitude sickness
• http://www.ismmed.org/np_altitude_tutorial.htm
• High Altitude Pathology Institute