Nepal Trekking Health Guide — Altitude Sickness, Diamox, Rabies & Pre-Trek Vaccines

Nepal trekking health — what to prepare for

Nepal is one of the most medically demanding trekking destinations in the world. The combination of extreme altitude, remote medical facilities, high rabies burden, and significant food and water contamination risk means pre-trek health preparation is not optional — it's essential.

Altitude sickness — the dominant health risk

Kathmandu (1,400 m) is below the height where altitude sickness usually starts: Canada's travel medicine committee says some people get symptoms from about 2,500 m, and the risk rises the higher and faster you climb. A rapid ascent to 3,400 m or more, such as flying into a high airstrip, puts you at high risk of headache, nausea, fatigue and poor sleep.

More dangerous: High Altitude Cerebral Edema (HACE) and High Altitude Pulmonary Edema (HAPE) — rare but life-threatening complications of rapid ascent to extreme altitude.

Altitude acclimatization rules

• Never ascend more than 300–500 m per sleeping elevation per day above 3,000 m
• "Climb high, sleep low" — ascend during the day, descend to a lower elevation to sleep
• Above 3,000 m, a rest day (2 nights at the same height) every 2 or 3 days, as Canadian guidance advises
• If AMS symptoms develop, do NOT ascend further until symptoms fully resolve

Acetazolamide (Diamox) — the prevention medication

Our physician can prescribe acetazolamide (the generic of Diamox; the brand is no longer sold in Canada), which speeds up acclimatization. Canadian guidance considers it for a rapid ascent above 3,000 m, a big one-day gain in sleeping height, or a past episode of altitude sickness, starting 24 hours before ascent. It does not replace a slow ascent. More in our altitude sickness guide. Common side effects: frequent urination, tingling in fingers/toes, altered taste of carbonated drinks. Well-tolerated by most trekkers.

Rabies — critical for Nepal trekking

Nepal has a high stray-dog burden — in Kathmandu streets, village trails, and teahouse routes. Dogs approach trekkers frequently. Pre-exposure rabies vaccination is strongly recommended because:

1. Stray dogs with potential rabies exposure are common on trekking routes
2. Rabies immunoglobulin (RIG) — needed post-exposure without prior vaccination — is frequently unavailable in remote trekking areas of Nepal
3. Pre-vaccination completed less than 3 years before a bite (or followed by a booster) means the bite requires only 2 booster doses (available anywhere) and no RIG, not the full post-exposure protocol

Other vaccines for Nepal

• Hepatitis A: All travellers
• Typhoid: All travellers — high burden in Nepal
• Dukoral: Optional (not routinely recommended)
• Japanese Encephalitis: Recommended for extended rural travel in Terai lowlands during monsoon

Emergency planning

For high-altitude trekking: confirm your travel insurance covers helicopter evacuation. Evacuation from remote trekking areas can cost $10,000–$30,000 USD. Carry a written emergency contact plan including the nearest hospital with altitude sickness treatment capability.

Book your Nepal trek consultation at Virtual Travel Clinic — we provide altitude sickness medication prescriptions (Diamox), pre-exposure rabies vaccination, and full pre-trek briefings. Serving Mississauga, Ottawa, and all of Ontario.

Sources: PHAC — Nepal Travel Health | CDC Yellow Book — Nepal