Recognizing the Symptoms
Altitude sickness symptoms usually begin within 6 to 24 hours of reaching a higher elevation. Milder cases of altitude sickness presents with:
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Headache
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Nausea
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Fatigue
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Dizziness
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Shortness of breath during exertion
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Difficulty sleeping
In some people, symptoms of altitude sickness progress to more severe forms like high-altitude cerebral edema (HACE) or high-altitude pulmonary edema (HAPE). Both of these condition require immediate medical intervention. Signs of these serious complications include
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Confusion
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Severe breathlessness at rest
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Loss of coordination.
Altitude Sickness
What Happens When You Climb Too High Too Fast
If you are planning to scale the Himalayas, trek the Andes, or even fly into high-altitude cities like La Paz or Lhasa, it is important to remember that altitude sickness is a real concern that shouldn't be underestimated. Altitude sickness, also known as acute mountain sickness (AMS), is your body’s way of responding to lower oxygen levels at elevations above 2,500 meters (8,200 feet).
Why Altitude Affects Us
At sea level, the oxygen saturation in the air is around 21%, to which the body is well-adapted. However, with increasing altitude, the atmospheric pressure drops, and this reduces the amount of oxygen for your lungs to absorb. In such a hypoxic environment, your body may react in ways that can range from mildly uncomfortable to life-threatening.
Altitude sickness is a condition that develops as the body struggles to acclimatize to the change in atmospheric pressure and declining oxygen levels. But not everyone who travels to high-altitude regions suffers from altitude sickness. Many factors, such as rapid ascent, dehydration, intense physical exertion, and a past history of acute mountain sickness can increase your risk.
How to Prevent It
The gold standard to prevent altitude sickness is to acclimatize. This can be done by:
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Ascending slowly: Ideally, it is recommended to not gain more than 300–500 meters (1,000–1,600 feet) of sleeping altitude per day once you are past 2,500 meters.
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Rest days: Incorporating rest days between your trek or climb can also help prevent altitude sickness from developing.
Other preventative strategies include:
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Hydration: Staying well-hydrated keeps circulation efficient, though you should be careful to avoid overhydration.
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Avoid alcohol and sedatives: These can depress the respiratory drive and can worsen symptoms.
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Medications: Acetazolamide (Diamox) can speed up the process of acclimatization. It works by making the blood slightly acidic, which then stimulates breathing and thereby improves oxygenation.
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For those with a past history of acute mountain sickness, preventive medication can be considered before reaching an altitude above 2,500 meters.
What to Do If Symptoms Start
The most important and first thing to do once you notice symptoms is to immediately stop ascending further. If you only have mild symptoms, these may improve with just rest and hydration. However, if your symptoms worsen or persist beyond 24 hours, the only reliable treatment is to begin descending. If available in higher altitudes, portable hyperbaric chambers can help simulate lower altitudes and serve as temporary management tools.
Therapy using oxygen can also help alleviate symptoms quickly, but it should never be used as a substitute for descent in moderate or severe AMS.
