Altitude Acclimatization – Overview

Altitude Acclimatization - overview

15 Sep 2022 Chandra Gurung


Everyone must monitor their health regularly when approaching terrains of higher altitudes. Altitude sickness can take a toll for the worse when left undiagnosed and neglected. Therefore, participants must administer proper care to understand what causes this phenomenon. At higher elevations, appropriate diagnoses for this sickness can only be made possible when you know the looming dangers of oxygen deprivation. So, Altitude Acclimatization plays a very serious role.

Once its symptoms sink in, there exists only a thin line between rationality and delirium. It is the main reason victims refuse care and attention, growing increasingly stubborn and socially withdrawn in the later stages of the illness.

Acute Mountain Sickness is estimated to affect 20% of people ascending elevations of 2500 meters hurriedly, a statistic that goes up to 40% for all those hasty travelers that gain elevations of up to 3000 meters during their trek or climb. Altitude Acclimatization is an essential precaution against undesirable ailments like abrupt cancellations in your journey and emergency evacuations due to an inability to proceed any further. 

Symptoms of Insufficient Altitude Acclimatization :

The onset of altitude sickness is characterized by a mild headache, which slowly worsens into a gnawing, migraine-like sensation. Other significant indicators include shortness of breath, cough, and chest tightness. A bluish-purple coloration on the lips is a common observation among patients who cannot adapt to the rapid ascent in altitude. The tell-tale signs of chronic altitude sickness are decreased levels of consciousness, nausea, anxiety, nervousness, physical/mental disorientation, and eventually hallucinations.

When your body cannot adapt to decreased atmospheric pressure (or a lower concentration of oxygen), noticeable changes are seen in a person’s demeanor, e.g., excessive perspiration, pale skin, in some cases— nose bleeding, and swollen hands/feet/face. Even worse, coughing up blood or sputum indicate an immediate need to evacuate the patient. ‘Paresthesia,’ a tingling ‘pins and needles sensation in your hands and fingertips, is another recurrent complication in individuals. 

Because of the symptoms that closely resemble other respiratory illnesses and disorders, this sickness was referred to as ‘high-altitude pneumonia’ in the early 19th century.


If the symptoms related to insufficient Altitude Acclimatization go unnoticed, conditions are aggravated, posing a threat to the permanent well-being of the person. It leads to more pressing health problems such as HACE (High Altitude Cerebral Edema) and HAPE (High Altitude Pulmonary Edema).

The region above an altitude of 8000 meters is referred to as the death zone, also called the ‘lethal zone,’ a term dubbed by Edouard Wyss-Dunant, a swiss doctor in 1953. Extended stays at such elevations without supplemental oxygen are detrimental to essential bodily functions and can ultimately lead to death.

Deleterious aftermaths of these severe health problems include permanent lung injury, respiratory failure, impairment of lung function, visual encumbrances, seizures, and psychosis. Cerebral and Pulmonary Edemas are caused by an accumulation of fluid in the brain or the tissues and airspaces of the lungs. These symptoms are heightened during the nighttime, causing suffocation and extreme weakness.

‘Cheyne-Stokes Respirations’ is another vital indication of a lack of Altitude Acclimatization, with the body being unable to cope with the lack of oxygen in the atmosphere. Similar to an episode of apnea and in a more severe form—a stroke, it can be identified by instability in respiratory control. Victims exhibit patterns of slow-deep breaths, followed by fast-shallow breathing, and ending with a period of a lapse in breathing entirely. This irregular breathing pattern occurs nocturnally (rare cases while awake), and an obstruction causes it to the cerebral artery (which supplies blood to the brain). 

Concerns for Maternal Health, Diabetic Patients:


Medical professionals strictly advise against high-altitude excursions for expecting mothers. Such a heedless act should never be attempted, as studies show that exposure to a significant increase in elevations (despite proper acclimatization) can seriously hinder fetal growth. Maternal health during gestation falls under a life-threatening spectrum when insufficient oxygen levels inhibit development. 


Altitude Acclimatization - Overview : Diabetes

In the case of diabetic patients, low temperatures paired with high altitudes cause inaccurate readings of the blood glucose in the body. Regions at higher elevations also increase the production of stress hormones within the body, which can, in turn, raise the overall blood sugar levels of the body. Counter-regulatory hormones can pose a threat to glycemic control, because of which you should frequently monitor blood glucose levels at higher altitudes. Reduced atmospheric pressure requires an appropriate compensation in insulin, which is why you should consult a doctor before embarking on your journey. 

Safety Measures: 

Altitude Acclimatization is a prerequisite to altitude ascents, especially for people living in lower elevations throughout the year. This demographic is particularly prone to afflictions of Altitude Sickness. 

How Does Your Body React to Higher Altitudes?

A decline in blood-oxygen levels (hemoglobin) is observed when ascending higher elevations of more than 2100 meters (6.890ft) above sea level. The human body makes up for this by suppressing the ‘non-essential,’ secondary bodily functions—such as slowing down digestion. Increased production of red blood cells into the bloodstream leads to a faster pulse, and the body secretes stress hormones like adrenaline, cortisol, and growth hormone. 

How Many Days Does It Take to Adapt Entirely to Elevation Changes?

According to the journal of physiology and pharmacology (Polish Physiological Society), a specific adaptation, i.e., red blood cell production within the body plateaus—is calculated by multiplying the altitude in kilometers by 11.4 days. For example: at 5000 meters, it takes 57 days to reach your maximum acclimatization level. 

What Is the Ideal Approach to Altitude Ascent?

After much experimentation, it is discovered that:

For the ordinary human being (excluding people who live all year round at elevations of 3500 meters+), a maximum of 500 meters gain in altitude daily is the safest margin, with minimal risks of facing altitude sickness. It is where the saying’ climb high-sleep low’ originates from. Aside from this, altitude acclimatization should be pre-planned, and people with prior episodes of altitude sickness should be paid special attention to. 

Additional Tips

  • Consume plenty of water, up to 3-4 liters daily.
  • Avoid Caffeine and Alcohol entirely because it causes dehydration.
  • Steer Clear of sleeping pills and sedatives.
  • Garlic or Garlic Soup should be an essential constituent of your diet. This bulbous plant (nicknamed the stinking rose) is a lifesaver and will help those who are disinclined toward pharmaceutical drugs. 
  • Sports clothes are warm, breathable fabrics and always ensure dryness.
  • Do not indulge in overexertion, which means carrying only compact, light weights below 15 kilograms (10 if you’re not the muscular type) 
  • Always include a rest day (halted ascent) every 3-4 days. 

Optionally you can introduce an altitude tent, which simulates a higher-altitude-like atmospheric pressure. This sealed tent can assist in altitude acclimatization in advance so that you can reach the optimal level of RBC production early on. 

Treatment and Medication:

General Trend

The ingestion of Acetazolamide (Ingredient), sold under the brand name Diamox, is widely practiced as a preventative and antidote for altitude sickness. Used commonly for quick ascents, it alleviates the symptoms of Altitude Sickness. This drug can be taken with or without food and swallowed as a whole (no breaking/chewing). Taking the medication for more than 3-4 days is not recommended. 

Taking the drug a day or two before your ascent aids in the process of Altitude Acclimatization, although it is not to be mistaken for an immediate cure for acute mountain sickness. Eating foods rich in potassium (leafy greens, dry fruits, and dairy) is advisable because the drug diminishes potassium levels in the blood. 

In any drug store, you can obtain this drug for under a dollar (US) (less than 100 Nrs). 

This medicine is not recommended for patients allergic to sulfa drugs/sulfonamides and those with severe kidney/liver problems. Blood thinners (anti-coagulants) cause a reaction to the drug, and you should never take the two together. 

Side Effects:

Abdominal cramps, fatigue, increased production of urine (diuresis), sleepiness, vomiting, loss of appetite, tinnitus, numbness, and blurred vision.  


Fonurit, Diakarb, Acetazolamide, Diuramid, Edemox, Acetamox, Didoc, Cidamex, Vetamox, Diutazol, Glaupax, Diureticum-Holzinger, Dazamide, Donmox, Diacarb, Ak-Zol.

In case of breathing issues at higher altitudes, Salmeterol can be used as a treatment for prompt relief of any shortness of breath, coughing, and/or chest tightness. You can also take Paracetamol/Aspirin to reduce fevers or pain. If symptoms persist and no improvement is observed in the patient’s condition, immediate descent is the wisest choice. A person always accompanies the ailing patient because delusions and altered states of consciousness are typical of this illness.

Emergency Measures:

Portable Hyperbaric Bag: The Gamow Bag

When the possibilities of immediate descent are unavailable, the last resort is to use an inflatable pressure bag. With this help, a condition (inverse to an altitude tent) is accomplished, and the patient is enclosed within the pack. A foot pump inflates the bag, and the pressure inside is regulated with a safety valve. Thanks to Igor Gamow (inventor), a professor at the University of Colorado, countless lives have been saved during high-altitude expeditions. 


Altitude Acclimatization - Overview : Conclusion

Altitude Acclimatization is a serious matter that can determine the success of any high-altitude endeavors, also life or death situations. The greatest challenge associated with oxygen deprivation is a weakened sense of perception, which causes them to lose a grip on reality. Rescuing individuals who face this illness is an ordeal in such cases. 

The only surefire solution to preventing altitude sickness is to formulate a comprehensive plan before climbing by addressing sufficient forethought to your itinerary. Hence, you should never attempt Mountaineering and Climbing without an experienced professional or a guide by your side.