Index
- What is altitude sickness?
1.1 But what does it entail?
1.2 From what height should you start paying attention? - How to recognize it?
2.1 Physiological symptoms
2.2 Serious consequences of altitude sickness
2.2.1 Characteristic signs and symptoms of HAPE
2.2.2 Characteristic signs and symptoms of HACE - Who needs to pay attention?
3.1 Established Risk Factors - How can it be prevented and avoided?
4.1 Climb to altitude slowly and step by step
4.2 The 300 meter rule: “Climb High, Sleep Low”
4.3 Stay hydrated
4.4 Avoid alcohol
4.5 Medicines to prevent altitude sickness - What to do if symptoms appear
- The role of Monte Rosa in scientific research linked to altitude sickness
- Conclusion and final advice
1. What is altitude sickness?
Altitude sickness, technically known as Acute Mountain Sickness (AMS), is an affecting syndrome when the human body is rapidly exposed to low oxygen pressures associated with high altitude.
Although air always contains approximately 21% oxygen regardless of altitude, barometric pressure decreases with increasing altitude, reducing the partial pressure of oxygen and, consequently, the amount of oxygen available to our bodies.
1.1 But what does it entail?
Simply, it means that your body will implement different physiological reactions to respond to the rapid change in altitude.
In essence, altitude sickness is a physiological condition linked to acclimatization to which you should pay close attention.
1.2 From what height should you start paying attention?
It is good to pay attention to this phenomenon for climbs above 2000 – 2500 meters, so if your intention is to climb the peaks of Monte Rosa it is necessary to know this phenomenon well.
2. How to recognize it?
2.1 Physiological symptoms:
These are the most common symptoms
-
- Headache: typically bifrontal, pulsating, aggravated by effort, coughing or sudden movements
- Gastrointestinal disorders: nausea, occasional vomiting, anorexia
- Fatigue: tiredness disproportionate to the activity carried out
- Sleep disorders: insomnia, frequent awakenings, periodic nocturnal breathing (Cheyne-Stokes breathing)
- Dizziness: feeling of instability, especially during rapid movements
- Subtle neuropsychological disorders: mild confusion, slowed decision-making, irritability
- Resting heart rate increased (>100 beats/min)
- Mild arterial hypertension
- Reduced oxygen saturation (SpO₂ <90% a 4.000m)
2.2 Serious consequences of altitude sickness
Altitude sickness itself is not risky and is easily preventable or treatable.
However, if the right attention is not paid, the situation can quickly worsen, leading to 2 possible serious consequences: HAPE, or high-altitude pulmonary edema, and HACE, or high-altitude cerebral edema.
2.2.1 Characteristic signs and symptoms of HAPE:
- Dyspnea disproportionate to effort, then also at rest
- Initially dry cough, then productive with foamy sputum
- Hemoptysis (presence of blood in sputum)
- Central cyanosis (bluish discoloration of lips and mucous membranes)
- Crackling rales upon auscultation of the chest
- Marked tachycardia (>110-120 bpm)
- Mild fever (up to 38.5°C)
- Possible evolution towards acute respiratory failure and shock
2.2.2 Characteristic signs and symptoms of HACE:
- Progressive alteration of the state of consciousness (from drowsiness to coma)
- Severe ataxia (inability to maintain balance)
- Uncontrollable nausea and vomiting
- Diplopia (double vision) and other visual abnormalities
- Focal neurological deficits
- Papilledema on fundus examination
- Nuchal stiffness (sign of meningeal irritation)
- Convulsions in the advanced stages
- Possible terminal brain herniation
Now let’s be clear, with this information we do not want to alarm anyone but only to make everyone aware of the dangers that the mountains, especially at high altitudes, imply and will always imply if attention is not paid to all the relevant factors and if every climb and preparation is not respected.
Preparation is in fact an essential element, and for this reason we have prepared a basic course that will allow you to learn how to climb while minimizing the risks and exploring these topics together with a UIAGM mountain guide.
If you want to find out more click here.
3. Who needs to pay attention?
Altitude sickness can hit anyone, from the most experienced mountaineer to the novice.
Susceptibility to altitude sickness is in fact influenced by multiple factors, some of which are well established by scientific research, while others remain controversial and debated.
3.1 Established Risk Factors
- Previous history of AMS: the most powerful predictor; those who have suffered in the past have a 3-5 times greater risk
- Ascension speed: direct correlation between rate of rise and incidence of AMS
- Absolute altitude reached: exponential risk above 3,500 meters
- Duration of exposure: Incidence increases in the first 24-48 hours at a given altitude
- Excessive physical exertion: Intense activity in the first 24 hours at altitude increases the risk
- Pre-existing medical conditions: chronic lung diseases (COPD, asthma), heart disease, sickle cell anemia
- Low altitude resident: those who usually live below 900 meters are more vulnerable if they do not establish an ascent plan with adequate stages
4. How can it be prevented and avoided?
4.1 Climb to altitude slowly and step by step
It’s important to let your body get used to the altitude and therefore one essential preparation of the stages is what they will do to get to the top.
How long does acclimatization take?
There is no single answer, it is a process that varies from person to person and the weather can vary greatly.
Wanting to give a necessary time range we can say that the body begins to acclimatise from the day after the climb and it can end too after 3 weeks.
4.2 The 300 meter rule: “Climb High, Sleep Low”
After 3000 m. it is essential to pay more and more attention to the difference in altitude you face.
A commonly used rule is to climb a maximum of 300 – 500 m. and to never sleep higher than 300 meters. compared to the previous night.
The “Climb High, Sleep Low” technique consists precisely of this: going up during the day and coming down for the overnight stay.
It is very important to follow this strategy especially if you plan to climb more than 500 meters in one day.
Plan to take longer nights’ rest if it is not possible to follow this strategy and in any case it would be a good idea to do them every 1000 metres.
Furthermore, if you start from sea level, consider whether to go up a day or two before to let your body get used to it.
4.3 Stay hydrated
At high altitudes, the cold and dry air accelerates the loss of fluids, often without us realizing it.
Breathing faster and urinating more frequently, natural conditions at high altitude, amplify this effect, increasing the risk of dehydration.
Maintaining a good level of hydration is essential for the correct functioning of the body, the transport of oxygen and effective acclimatization, thus reducing the chances of incurring altitude sickness.
4.4 Avoid alcohol
Alcohol and caffeine can negatively affect the body at high altitude.
Alcohol promotes dehydration and dilates blood vessels, increasing the dispersion of body heat and making it more difficult to maintain the ideal temperature.
Caffeine, on the other hand, has a vasoconstrictor effect and can contribute to dehydration, as well as potentially altering sleep, a crucial element for good acclimatization.
To best tackle the climb, it is advisable to avoid both of these substances before and during the ascent, favoring instead water and drinks rich in electrolytes to support hydration and general well-being.
4.5 Medicines to prevent altitude sickness
Acetazolamide (Diamox)
Acetazolamide remains the drug of first choice for the prevention of AMS, with a level of evidence IA according to international guidelines.
Mechanism of action:
- Inhibition of carbonic anhydrase
- Metabolic acidosis that stimulates ventilation
- Diuresis with reduction in plasma volume
- Reduction in the production of cerebrospinal fluid
- Improvement of periodic nocturnal breathing
Dexamethasone
Dexamethasone is effective in preventing AMS but with narrower indications than acetazolamide.
Specific indications:
- Rapid ascents required (evacuations, rescue missions)
- Short duration of exposure at high altitude (<72 hours)
- Intolerance to acetazolamide
- History of HACE in previous exposures
*Obviously each of these drugs should be taken only and exclusively under medical advice.
5. What to do if symptoms appear
If even just one of the symptoms described appears, it is good practice to intervene immediately.
Clearly here too the intervention varies from case to case, it is certainly advisable to lose altitude quickly when even slightly more serious symptoms are felt.
6. The role of Monte Rosa in scientific research linked to altitude sickness
In 2005 Monte Rosa was a center for scientific research and experimentation by the Focus team and a group composed of researchers from the Italian Auxological Institute and the Department of Clinical Medicine, Prevention and Health Biotechnology of the University of Milan-Bicocca.
(source: https://www.focus.it/ambiente/natura/scienza-sul-monte-rosa)
The research was aimed at studying the effects of high altitude to understand if it was possible to improve the lives of people suffering from heart disease and/or diabetes.
In addition to using common medical equipment for activities such as monitoring, the team also tested the effects of a special t-shirt capable of detecting cardiac activity, an idea initially born for astronauts.
“In fact, on the summit of Monte Rosa, people live in extreme conditions, since the air pressure is about half that at sea level and, above all, because the amount of oxygen in the air is reduced (oxygen is a relatively heavy gas, which thickens in the lower layers). These studies could find application in the treatment of diabetic and heart disease patients, since they also suffer from so-called hypoxic conditions, i.e. lack of oxygen in the blood.”
– Focus
7. Conclusion and final advice
Tackling an excursion or ascent at high altitude, such as on Monte Rosa, requires adequate preparation to avoid the risks associated with altitude sickness.
Respecting the acclimatization rules, correct hydration and awareness of the symptoms are fundamental elements for living the experience safely.
These elements are essential if you want to reduce them to a minimum.
High altitude does not forgive improvisation and underestimation of the body’s signals.
Even the most experienced mountaineers can suffer from altitude sickness if they do not respect the acclimatization times or tackle the climb too quickly.
For this reason, it is essential:
- Plan your itinerary carefully, including acclimatization stages
- Recognize the first symptoms of altitude sickness and act immediately
- Follow progression rules at altitude, such as the “Climb High, Sleep Low” technique
- Don’t underestimate the importance of an expert guide in the high mountains
If you want to learn more and better prepare yourself for a conscious ascent, we have created a specific course with a UIAGM mountain guide, in which you can learn everything you need to face altitudes without risks.
Do you want to climb Monte Rosa or tackle a high-altitude excursion taking all the necessary measures to minimize risks?
Get ready the right way with our mountaineering course, led by a UIAGM expert.
What will you get from the course?
- You will learn to experience the mountains with awareness
- You will learn how to navigate environments far from your comfort zone
- You will learn what equipment to use and how to use it
- You will know the freedom of feeling good and connected to nature in non-anthropized environments
Don’t let altitude sickness ruin your adventure. Get ready with the support of professionals to face the mountains with awareness and tranquility.
Book your place on the course now by clicking here
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