injuries and poisoning
Altitude Illness
Prevention of Altitude Illness
The best way to prevent altitude illness is to ascend slowly. The altitude at which a person sleeps is more important than the maximum height reached during the day. Control of the rate of ascent (called graded ascent) is essential for activity any higher than 8,000 feet (2,500 meters). Above 10,000 feet (3,000 meters), climbers or trekkers should not increase their sleeping altitude by more than 1,600 feet (500 meters) per day and should include a rest day (sleep at the same altitude) every 3 to 4 nights before they sleep at any higher altitudes. If people cannot limit each day's ascent to less than 1,600 feet (500 meters), they should limit their average ascent over the entire ascent to less than 1,600 feet (500 meters) per day. This may require adding rest days. During rest days, day hikes to higher elevations are acceptable as long as people return to the lower level for sleep. People vary in their ability to ascend without developing symptoms. Thus, a climbing party should be paced for the member who acclimatizes to high altitude the slowest. Acclimatization reverses quickly. If acclimatized people have descended to low levels for more than a few days, they must once more follow a graded ascent when they reascend. Acetazolamide, which can be started the night before the ascent, can reduce the likelihood of altitude illness. If taken after illness has begun,acetazolamidemay help lessen symptoms.Acetazolamideshould be stopped when descent is initiated or after a few days have been spent at the peak elevation.Dexamethasone, an alternative toacetazolamide, can also reduce the likelihood of acute mountain sickness and treat its symptoms. Taking analgesics such as Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) may help prevent high-altitude headache. People who have had previous episodes of high-altitude pulmonary edema should be alert for any symptoms of a recurrence and descend immediately if symptoms occur. Some doctors also recommend such people takenifedipineortadalafilby mouth as a preventive measure. Avoiding strenuous exertion for a day or two after arrival may help prevent altitude illness. Heavy alcohol consumption, opioids, and sedatives should be avoided, particularly shortly before sleep. Habitualcaffeinedrinkers should be aware of the possibility ofcaffeine-withdrawal headaches if they stop consumingcaffeineon their excursion. Although physical fitness enables greater exertion at altitude, it does not protect against any form of acute altitude illness.Acetazolamidecan be used to improve sleep, which is disturbed for many people traveling to high altitude. 