Breathtaking landscapes, clean air, cool summer temperatures: the charm of the high mountains attracts a growing number of people, thanks to increasingly modern infrastructure and equipment that allow you to reach the altitudes above 2,500 metres. The fact remains that exceeding certain altitudes must be faced with awareness and preparation and cannot be lived as a hit and run tourism experience as sometimes happens, even with serious consequences. THE risks they are different, starting with the problems that an unfamiliar altitude can cause to the body.
In this article
Altitude sickness: what it is and symptoms
“When you go up the barometric pressure decreases and, with it, the pressure of oxygen inside our body also drops,” he explains Lorenza Pratalicardiologist at the Institute of Clinical Physiology of the CNR in Pisa and president of Italian Society of Mountain Medicine – SIMeM.
«Although the quantity of oxygen in the air always remains 21%, due to the reduction in pressure it is not possible to store the same quantity that is introduced with breathing at sea level. This condition is called hypoxia and triggers a series of responses in the body to adapt. In some cases this acclimatization process can instead evolve into some pathological conditions. Among these, the altitude sickness – or rather, acute high altitude sickness – which can develop in case of exposure at altitudes above 2,500 metreswith an estimated incidence of around 30% in our Alps. It is a syndrome characterized by the presence of headache associated with gastrointestinal disturbances (nausea vomiting, diarrhea), sense of excessive fatigue, light-headedness and/or dizziness, sleep disorders».
Prevent altitude sickness
Acclimatization
To prevent altitude sickness, you need to adapt gradually. “L’acclimatization, well known to people who climb very high altitudes, is unfortunately little used by those who go to our 4,000m, where there is often a race to see who climbs faster», continues the SIMeM president. “Especially because this syndrome can affect anyone, even expert mountaineers who have made the same climb several times. Man does not always have the same responses to exposure to altitude and this variability can be caused by contingent external situations, for example lower temperatures, or by particular momentary health conditions, such as a simple cold which can alter responses to ‘share exposure’.
Acclimatization consists of a gradual ascent with short stops: once you have exceeded 2,500-3,000 meters you should increase the altitude no more than 500-600 meters and stop to sleep for one night. Also they should provide rest days every three or four days, during which you should sleep at the same altitude for at least two consecutive nights. In general, the slower the ascent, the longer the acclimatization time and the lower the risk of altitude sickness and symptoms.
Precautions to be taken during the ascent
In addition to acclimatization, to prevent altitude sickness it is important, during the ascent:
hydrate: to get an idea of the quantity, drink at least three liters of water a day for altitudes above 3,000 metres;
avoid overexertion considering the reduction of oxygen, not repeating its performances that are normally done at sea level;
do not drink alcohol because alcohol may depress the compensatory respiratory response, especially at night.
Drugs as prophylaxis
For any use of drugs as prophylaxis (for example, acetazolamide o betametasone) it is necessary to contact a doctor competent in mountain medicine to evaluate the indication and methods of use. People who have had repeated episodes of acute high-altitude illness must plan the ascent method with a specialist in the sector and implement any prophylaxis, informing the mountain guide if they are accompanied. If after a few hours of staying at a height the symptoms of altitude sickness should appear, a few precautions should be taken:
Rest. If the symptoms worsen so much that you are unable to carry out normal activities, then rest is not enough, but it is advisable to descend at least 500 meters slowly, without making excessive effort.
Take drugs. When needed, pain relievers such as ibuprofen o paracetamol for headache or antiemetics to counteract nausea, but the use must be agreed with your doctor before going up to high altitudes. If the headache, despite pain relievers, does not go away or gets worse, it is advisable descend at least 500 meters. Continue to hydrate: it is essential because more liquids are dispersed with the dryness of the air and with the more frequent breathing.
If the symptoms worsen and worrying changes in mood or drowsiness are noticed, it is better to call the emergency services.
Who should avoid exceeding 2,500 meters
At high altitudes, blood pressure increases proportionally to the altitude reached, and this happens above all at night and more easily in older people. For this reason, the cardiovascular risk in hypertensive individuals who wish to exceed 2,500 meters must be carefully evaluated with the doctor, arranging a possible adjustment of the pharmacological therapy.
Other conditions that make climbing to high altitudes contraindicated, even by car or cable car, are:
decompensated heart failure and unstable angina; pulmonary hypertension, whether or not associated with chronic obstructive pulmonary disease advanced; having suffered a myocardial infarction or stroke in the previous 90 days; untreated high-risk cerebrovascular abnormalities (aneurysms, arteriovenous malformations); neurological problems such as poorly controlled seizures; high risk pregnancy.
«Who suffers from migraine with aura should limit prolonged stays at high altitudes, due to an increased risk of cerebrovascular events, especially if smokers, obese, hypertensive or women taking estrogen-progestogens (contraceptives or replacement therapies in menopause, for example),” adds Lorenza Pratali. «It should be kept in mind that the lower concentration of oxygen at altitude can increase the frequency and intensity of the attacks and therefore a conversation with the specialist is recommended to evaluate any prophylaxis and to agree on the medicines to take with you».
Who can exceed 2,500
Children
Children between two and five years of age can climb up to 2,500-3,000 metres, but caution is needed since at this age it is not always easy for children to describe and communicate any symptoms. In the age group between five and ten years this altitude is generally well tolerated, even if it is always necessary to be vigilant about a possible onset of altitude sickness. Therefore, when you decide to go to high altitude with children, it is advisable to make a gradual and slow ascent, with several stops (there are intermediate stations of the cable cars that take you above 2,500 metres), to allow them to acclimatise.
Elderly people
And what about the elderly? It all depends on the individual state of health, but it must be kept in mind that, even in the case of a healthy person, after a certain age some physiological mechanisms undergo variations. If statistically after age 60 altitude sickness is less frequent, episodes of hypothermia, however, are greater because thermoregulation changes with age. In addition, cardiac output decreases, lung capacity decreases, vessel walls stiffen. “They are all changes that can lead to excessive fatigue,” concludes the specialist. «For this reason it is always necessary to consult with your doctor before venturing at high altitude».
How to reach the summit without getting altitude sickness
Here is an example of acclimatization that can be practiced in our mountains. If a person decides to climb to the top of the great paradise (altitude 4,061 meters), it would be advisable in the previous weekends to carry out climbs at increasing altitudes.
We can hypothesize a first trip between 2,500 and 3,000 meters with an overnight stay between 2,500 and 2,700 metres; in the following weekend a climb between 3,000 and 3,500 with overnight stays at 2,700-2,800. In the third weekend, at this point, good acclimatization was obtained and it was possible to climb safely to the top by dividing the climb into two days with an overnight stay in one of the Gran Paradiso refuges. Otherwise, if you don’t have all this time available, the indication would be to climb above 4,000 by step climbing for a total of four days.