10–15 trekkers die on Nepal's trails annually — most preventably. Altitude Mountain Sickness (AMS) is the primary killer above 3,000m. Know the symptoms, the rules, and the emergency response.
Based on the Lake Louise AMS Score (0–12). Score ≥3 with headache = AMS. Score ≥5 = severe AMS. Descend.
Headache
Gastrointestinal
Fatigue/Weakness
Dizziness/Lightheadedness
Sleep Quality
0–2
Normal
No AMS
3–4
Mild AMS
Rest, no ascent
5+
Severe AMS
Descend now
500m Sleep RuleCritical
Above 3,000m, sleep no more than 500m higher than the previous night. The golden rule of altitude.
Climb High, Sleep LowCritical
You can climb higher during the day, but return to a lower elevation to sleep. Used on EBC and all expeditions.
Namche Acclimatization (EBC)
Spend 2 nights in Namche Bazaar (3,440m). On the rest day, hike to Everest View Hotel (3,900m) then return.
Dingboche Rest Day (EBC)
Spend 2 nights in Dingboche (4,410m). Day hike to Nagarjun Hill or Chukung Ridge on rest day.
Diamox (Acetazolamide)
250mg twice daily starting 24h before ascent. Reduces AMS risk significantly. Consult your doctor before taking.
Hydration
Drink 3–4 litres of water per day above 3,000m. Dehydration significantly accelerates AMS symptoms.
These are medical emergencies. HAPE kills faster than any other altitude illness.
Required Action:
DESCEND IMMEDIATELY — minimum 1,000m. Do not wait for morning. Give dexamethasone 8mg if available.
Required Action:
DESCEND IMMEDIATELY — most dangerous altitude illness. Nifedipine 30mg if available. Helicopter evacuation if descent impossible.
Elevation at each major rest point on the Everest Base Camp trail
Helicopter Rescue Fraud
Strangers approaching trekkers claiming to 'coordinate' rescue and demanding payment. Never pay cash to an intermediary — call the rescue company directly or through TrekkrOS.
'Free Oxygen' Scam
Tea houses near high camps claiming to offer emergency oxygen for a fee they collect before delivery. Legitimate oxygen is arranged through medical staff or guides only.
Fake Medical Certification
Unlicensed 'doctors' at high-altitude checkpoints offering medical clearance certificates for trekking. NTB does not issue medical clearance at checkpoints.