ACUTE MOUNTAIN SICKNESS

Understanding High-Altitude Acclimatisation

Our bodies are capable of adjusting to high altitudes, but this process takes time. Acute Mountain Sickness (AMS) occurs when the body struggles to adapt to higher elevations, typically during rapid ascents above 2,000 meters.

AMS happens because fluid begins to accumulate between the body’s cells, most commonly affecting the lungs and brain. Early warning signs include headache, extreme fatigue, and loss of appetite.

If you notice mild symptoms, it’s important to pause your ascent and stay at your current altitude until your body adjusts. To help your body acclimate safely, it is recommended that once you are above 3,000 meters, you hike moderately upward by no more than 300 meters per day, allowing your system the time it needs to adapt.

Proper acclimatisation ensures a safer, more enjoyable high-altitude adventure and reduces the risk of severe altitude-related illnesses.

High-Altitude Sickness: Symptoms, Risks, and Prevention

Climbing or trekking at high altitudes can put your body under extreme stress. Understanding the different types of altitude sickness and how to respond can save lives.

High-Altitude Pulmonary Edema (HAPE)

HAPE occurs when fluid accumulates in the lungs. Early recognition is critical.

Symptoms include:

1: Shortness of breath, even at rest

2: Persistent, dry, and irritating cough, which may later produce pink frothy sputum

High-Altitude Cerebral Edema (HACE)

HACE develops when fluid builds up in the brain, causing potentially life-threatening complications.

Symptoms include:

1: Severe headache

2: Nausea and vomiting

3: Loss of appetite

4: Fatigue and extreme drowsiness

Impaired balance and coordination, which may lead to falls or coma

Acute Mountain Sickness (AMS)

AMS is the most common form of altitude sickness and can appear within hours after reaching a higher elevation.

Symptoms include:

1: Shortness of breath

2: Headache

3: Nausea or loss of appetite

4: Fatigue

Prevention and Safety Rules

To minimise the risk of high-altitude sickness:

1: Descend immediately if you notice early symptoms such as shortness of breath, cough, headache, nausea, or fatigue.

2: Do not ascend to sleep at a new height if AMS symptoms appear.

3: Gradual acclimatisation is essential when trekking above 3,000 meters.

Treatment

The key to treating altitude sickness is: descend, descend, descend!

If descending is impossible, use:

1: Portable Altitude Chamber (PAC) to simulate lower altitudes and increase oxygen intake

2: Supplemental oxygen for 1–4 hours, depending on severity

Medication:

Diamox (Acetazolamide): 125 mg every 12 hours can help prevent or treat mild symptoms. Mild tingling in the hands or feet may occur.

For direct flights to high-altitude areas like Everest Base Camp or Shyangboche (above 3,000 m), taking Diamox before arrival is recommended.

Key Takeaways

1: Monitor your body for early warning signs

2: Never ignore symptoms — high-altitude sickness can escalate quickly

3: Descend promptly and seek medical help if symptoms worsen

By following these guidelines, trekkers and climbers can enjoy high-altitude adventures safely while reducing the risk of life-threatening complications.