Altitude Sickness on Bhutan Treks

Altitude sickness is a real consideration on many Bhutan treks — several routes cross passes above 4,500m, and the Snowman Trek spends weeks above 4,000m. But with proper acclimatization and experienced guides, it is entirely manageable. Here's what you need to know.

What Is Altitude Sickness (AMS)?

Acute Mountain Sickness (AMS) occurs when the body doesn't adapt quickly enough to reduced oxygen levels at high altitude. It typically begins above 2,500m and becomes a serious risk above 3,500m. AMS is not about fitness — even very fit trekkers can be affected.

Symptoms (mild to severe)

• Mild AMS: Headache, fatigue, loss of appetite, slight nausea, poor sleep, dizziness
• Moderate AMS: Persistent headache not relieved by ibuprofen, vomiting, shortness of breath at rest, inability to walk straight
• Severe AMS / HACE / HAPE: Confusion, loss of coordination, severe breathlessness at rest, pink frothy sputum — requires immediate descent and emergency evacuation

Which Bhutan Treks Carry the Highest Risk?

Trek	Max altitude	AMS risk level	Notes
Snowman Trek	5,320m (Rinchenzoe La)	High	Weeks above 4,000m; multiple passes above 5,000m
Laya Gasa Trek	5,005m (Karakachu La)	High	Remote; evacuation difficult
Jumolhari Trek	4,930m (Bhonte La)	Medium–High	Camp at 4,080m; proper acclimatization day included
Nub Tshonapata Trek	4,800m (Tshonapata Lake)	Medium–High	Remote high lake; limited evacuation options
Dagala Trek	4,520m (Dagala)	Medium	Shorter; enough time to acclimatize
Druk Path Trek	4,210m (Phajoding)	Low–Medium	Gradual ascent from 2,300m; well-managed
Soi Yaksa Trek	3,900m	Low	Mostly forested; good introduction
Merak Sakteng Trek	3,500m	Low	Eastern Bhutan; lower overall elevation
Chele La Trek	3,988m	Low	Starts at high pass; day-hike friendly

How We Design Itineraries for Acclimatization

The standard rule for safe acclimatization is "climb high, sleep low" — and never increase sleeping elevation by more than 300–500m per day above 3,000m. All Trek Bhutan itineraries are built around this principle.

What we build into every high-altitude trek

• Acclimatization days — dedicated rest days at key altitudes (e.g. Base Camp on Jumolhari Trek)
• Gradual elevation gain — controlled daily ascents, especially in the first 3–4 days above 3,000m
• Pulse oximeters — all guides carry them to monitor oxygen saturation at camp each evening
• Diamox on hand — emergency supply available for trekkers who develop AMS mid-route
• Flexible itineraries — we can add extra rest days without penalty if a trekker needs more time
• Helicopter evacuation — our emergency protocol includes helicopter access where terrain and weather allow

How to Prepare Before You Arrive

Before the trek

• Arrive in Paro 1–2 days early to acclimatize at 2,200m before heading into the mountains
• Consult your doctor about Diamox (acetazolamide) — a prescription medication that can speed acclimatization
• Avoid alcohol for the first 48 hours at elevation
• Stay well-hydrated — aim for 3–4 litres of water per day on trek
• Get travel insurance that covers high-altitude trekking and emergency helicopter evacuation

During the trek

• Tell your guide immediately if you develop any AMS symptoms — even a mild headache
• Never try to push through AMS to keep up with a group schedule
• Eat even if your appetite is reduced — your body needs fuel at altitude
• Move slowly on ascent days — there's no prize for arriving at camp early and exhausted

Is It Safe to Trek in Bhutan with a Medical Condition?

Many trekkers with conditions such as mild asthma, hypertension, or diabetes complete Bhutan treks successfully. However, anyone with heart or lung conditions should consult a doctor specialising in altitude medicine before booking. We're happy to discuss itinerary modifications (lower maximum altitudes, extra rest days) to accommodate medical needs — just let us know when you enquire.