Altitude Sickness Can Be Fatal: Decoding Symptoms, Prevention and Emergency Response

Words: Eric Wong
Editor: Maverick Au
Photos: Eric Wong

Risk Management

Risk management is essential adult knowledge—and I'm not talking about financial investments, but mountaineering.

Snow-clad mountains harbor multiple hazards: altitude sickness, rockfall, crevasses, avalanches, hypothermia, and frostbite.

Before any ascent, thorough understanding of potential risks and rigorous risk management are imperative. Otherwise, a single accident could be fatal.

Island Peak, standing at 6,189 meters, is a popular mountaineering destination for Hong Kong climbers. Yet I’ve witnessed many attempting it unprepared, succumbing to altitude sickness.

The Link Between High Altitude and Sickness

During a recent internship with Dr. Chu Cham-lun—a physiotherapist specializing in altitude medicine—I deepened my understanding of mountain illnesses.

This article focuses on altitude sickness; crevasse risks, hypothermia, and frostbite will be covered separately. 

Altitude sickness is common and can affect anyone, even Sherpas without proper acclimatization.

Its severity correlates with four altitude zones:

1 .High Altitude: 1,500–3,500m

2. Very High Altitude: 3,500–5,500m

3. Extreme Altitude: 5,500m+

4. Death Zone: 8,000m+

Note: The Alps (max 4,800m) can trigger sickness without acclimatization, despite shorter ascents.

Symptoms and Risks

Symptoms arise when ascending too rapidly, denying the body time to adapt to low oxygen.

Susceptibility varies by physiology; obesity increases risk. Three primary conditions occur:

 1. Acute Mountain Sickness (AMS)
Symptoms: Headache, nausea, fatigue.
Action: Monitor closely; if symptoms persist, descend immediately to avoid progression to HACE/HAPE.

 2. High Altitude Cerebral Edema (HACE)
Symptoms: Confusion, hallucinations, loss of coordination.
Critical: May present without AMS warning. Observe teammates for mental status changes. 

Immediate descent is non-negotiable.

 3. High Altitude Pulmonary Edema (HAPE)
Symptoms: Coughing pink froth, cyanosis, irrational behavior.
Fatal Risk: Often coexists with HACE. Descent must begin at first sign.

Prevention: Acclimatization Protocol

 1. Climb High, Sleep Low: Limit daily ascent to ≤600m. Sleep at lower elevation. Experts may push to 1,200m; novices must cap at 600m.

 2. Hydrate Aggressively: Maintain clear urine.

 3. Stay Active, Limit Sleep: Light daytime activity boosts adaptation; sleeping depresses respiration.

 4. Train for Survival: Fitness won’t prevent sickness but enables self-rescue.

Treatment: Three Non-Negotiables

1. Descend Immediately at symptom onset. Never rely on helicopter rescue (weather-dependent).

2. Acetazolamide (Diamox): For prevention/mild symptoms. Consult your doctor first—contraindications exist.

3. Reject Unproven Remedies: Rhodiola rosea lacks clinical evidence.