The colloquially called mountain sickness or altitude sickness is the lack of adaptation of the organism to the lack of oxygen (hypoxia) at higher altitude. It is a very common mistake to think that the amount or concentration of atmospheric oxygen decreases with altitude. Actually, the oxygen concentration is always the same (approximately 21%) regardless of altitude. What happens is that, as we ascend, there is a progressive decrease in atmospheric pressure and in the partial pressure of oxygen in the air that we inspire.
For some time now, the mountain teams have experienced great improvement and the mountaineers are getting better and better prepared. There are more routes to climb the most complicated mountains, although in the high mountains there is still a high rate of accidents on the climbs. According to studies, the main cause of death in high mountains is not wounds or exhaustion, but pathologies derived from altitude, especially cerebral and pulmonary edema.
The incidence of altitude sickness varies greatly from one person to another because some withstand rapid ascension better than others. It appears after 6 or 10 hours, it is more frequent in children under fifty years of age and in subjects who usually reside at less than 1,000 meters altitudes. A good fitness level does not prevent from the risk of altitude sickness as it can affect even the most experienced athletes.
Symptoms of altitude sickness
Mountain sickness can start being felt from 2,500-3,000 meters above sea level. It should be noted that many ski resorts are within this altitude range and that persons who are more sensitive can start feeling the first symptoms even at lower altitudes. The mildest symptoms are sleeping difficulty, dizziness, fatigue, headache, loss of appetite, nausea or vomiting and tachycardia
As for the severe symptoms, the bluish coloration of the skin (cyanosis), pectoral stiffness or congestion, confusion, cough, decreased consciousness, paleness, absolute inability to walk and respiratory distress are included. If there is no solution, it will evolve to more severe complications, so treatment should be urgently initiated.
How to act against altitude sickness
The first rule that should be applied to any problem derived from a mountain sickness is the descent to a lower elevation. The second measure is to administer oxygen through a mask. The practice of these two elementary measures is more than enough to solve most of the cases. If it is not resolved the patient must be urgently evacuated to a hospital with facilities to treat acute mountain sickness so as to avoid the risk of cerebral and pulmonary edema which is potentially fatal if not treated on time.
Tips to avoid altitude sickness
The best recommendation is to make a gradual ascent. The first and most important thing is to climb relatively slowly, performing adequate acclimatization periods of 2 to 3 days at a certain height (starting from 2,000 m). The following ascent rates are advisable: up to an average of 340-400 meters up to 5,000 meters, from 5,000 m to 6,000 m, ascend 250 meters per day; and above 6,000 m, ascend a maximum of 150-200 m per day.
Rest and hydration
In case of problems, it is essential to descend to a lower level than the one acclimatized and rest for 24 or 48 hours before resuming the ascent. If the symptoms are severe, start the descent immediately, always accompanied. In these situations, you have to drink a lot of liquid (at least 3 or 4 liters a day), avoid drinking alcohol and follow a hyperglycemic diet, rich in sugars and carbohydrates.
Profiles with risk
People with heart and lung diseases are at greater risk even if they have been treated successfully. Pregnant women, children, people with high blood pressure or with sleep apnea problems and those who have had altitude sickness before have a higher risk of suffering of mountain sickness and they should be particularly careful .
Prior recognition is vital
Although altitude sickness does not depend on the physical form of the person and can affect even the most experienced athletes, what is certain is that, as in any other athlete, exhaustive medical-sports examination will help detecting pathologies that predispose to altitude sickness. These include chronic heart and lung diseases such as angina pectoris, chronic bronchitis, emphysema, and some people with severe asthma, anemia, including sickle cell anemia (low blood hemoglobin content).