Managing high altitude

Acute mountain sickness is the headline hazard on these records. Elevation figures below are DataPoints from each trail page — not a guarantee that you will or will not get ill. NHS guidance (checked 2026-08-25) treats altitudes usually above 2,500 m as the risk band and tells travellers to see a GP or travel clinic for personal advice. That is public-health information, not a desk diagnosis.nhs.uk · 2026-08-25

Elevation facts from the records

Everest Base Camp Trek high point: 5,292 m (copernicus-dem:glo-30; verified 2026-08-24). Length on this record is 42.9 km from a schematic village line — not a walking distance. The elevation samples are an 8-point GLO-30 sample of those pins, not a walking profile. typicalDays 13 is the recognised teahouse itinerary with acclimatisation, not an official park duration statute. Schematic vertices on the stored profile:

• 0 km → 2,840 m
• 6.1 km → 2,641 m
• 13.4 km → 3,455 m
• 19.7 km → 3,867 m
• 28.7 km → 4,315 m
• 35.3 km → 4,917 m
• 39.4 km → 5,149 m
• 42.9 km → 5,292 m

Annapurna Circuit is a mapped OpenStreetMap relation (relation 1187310), not a schematic village line. Length on this record is 334.1 km (osm:relation:1187310; verified 2026-08-20; provisional). High point DataPoint: 5,385 m (copernicus-dem:glo-30; verified 2026-08-20). The named pass on the record is Thorong La, cited at 5,416 m — a textbook acclimatization case. The DEM sample sits 31 m under that Wikipedia figure; the record leaves Copernicus in place rather than overwriting the DataPoint. The stored profile is a dense GLO-30 sample of the OSM line, not a sleeping-altitude itinerary, so it is not reprinted here as daily camps. typicalDays 28. Route type on this record is point-to-point (not a closed loop).en.wikipedia.org · 2026-08-24

Manaslu Circuit high point: 5,151 m (copernicus-dem:glo-30; verified 2026-08-25) — Larkya La band on a Copernicus GLO-30 sample of the OSM line. The stored profile is a dense DEM sample of that line, not a sleeping-altitude itinerary, so it is not reprinted here as daily camps. typicalDays 14. Route type on this record is point-to-point (not a closed loop).

Annapurna Base Camp Trek high point: 4,130 m (https://en.wikipedia.org/wiki/Annapurna_Sanctuary; verified 2026-08-24). Length and cumulative ascent on this record remain seed approximations until an OSM line is ingested. The stored profile is a schematic of published village elevations, not a surveyed walking profile. typicalDays 7.

• 0 km → 1,070 m (seed approximation)
• 12 km → 1,540 m (seed approximation)
• 24 km → 2,170 m (seed approximation)
• 38 km → 2,610 m (seed approximation)
• 52 km → 3,200 m (seed approximation)
• 64 km → 3,700 m (seed approximation)
• 70 km → 4,130 m (seed approximation)

Acclimatization practice — not a prescription

Everest Base Camp Trek: Altitude / acute mountain sickness above ~3,000 m is the headline hazard. Wikivoyage: even the fittest are prone; Namche sits around 3,440 m and an acclimatisation rest day is recommended; if unwell, return to lower altitude (https://en.wikivoyage.org/wiki/Everest_Base_Camp_Trek, checked 2026-08-24, CC BY-SA). That Namche rest-day language is on the record, citing Wikivoyage (CC BY-SA). It is widely published pacing, not a medical order from this desk.

Annapurna Circuit: Altitude illness at Thorong La (5,416 m). Wikipedia Thorong La, https://en.wikipedia.org/wiki/Thorong_La, checked 2026-08-24. The stored typicalDays 28 is a long staged itinerary, not a park duration statute. This catalog does not hold a sourced Manang rest-day note on this record, so this page does not invent one. Gradual gain toward Thorong La is the pattern the length and typicalDays imply; NHS staged-ascent guidance below is the public-health frame, not a prescription.

Annapurna Base Camp Trek: Altitude illness above 3,000 m (Wikivoyage Annapurna Sanctuary trek; Wikipedia Sanctuary infobox 4,130 m, checked 2026-08-24)

Manaslu Circuit: Altitude / AMS at Larkya La (published ~5,106 m; GLO-30 high 5,151 m on this line). Surface as a safety fact.

NHS altitude-sickness guidance (checked 2026-08-25) includes: travel to high altitude slowly; spend a few days below 2,500 m before going higher; above about 3,000 m, rest at the same altitude every 3 to 4 days; try not to sleep more than 500 m higher than the previous night once above 3,000 m; do not travel from below 1,200 m to above 3,500 m in one day. “Climb high, sleep low” is the common-language version of that staged-ascent idea. Follow NHS / a clinician, not this page, if you become unwell.nhs.uk · 2026-08-25

Remote evacuation

Communication and rescue on these corridors are limited. AMS can become life-threatening; descent is the first-line response in the public guidance cited above, and helicopter or trail evacuation is not a plan this desk can promise.

Manaslu Circuit: Remote corridor with limited rescue; seasonal snow on the pass is a wilderness condition. Restricted-area access is agency-issued RAP (NTB trekking-permit page, checked 2026-08-25) — a logistics and safety rule, not a fee table. Permit amounts live on the Nepal trekking permits guide.ntb.gov.np · 2026-08-25

Everest Base Camp Trek also notes weather-dependent Lukla flights and cold, remote lodges on the upper valley — delays of days are published on the record. That is access reality, not an altitude treatment.

Annapurna Circuit: Altitude illness at Thorong La (5,416 m). Wikipedia Thorong La, https://en.wikipedia.org/wiki/Thorong_La, checked 2026-08-24. Communication and rescue on the Marsyangdi–Kali Gandaki corridor are not a plan this desk can promise. ACAP is recorded as required on this walk (ACAP (NTNC entry permit)); TIMS is noted as widely used on the corridor, with no official TIMS tariff fetched on the record. This page does not quote permit amounts — those live on the Nepal trekking permits guide. Access on the record: Road to Besisahar, then jeep up the Marsyangdi valley. Base is the stored OSM start, not a named village invented here.

Also in this desk: Everest Base Camp Trek · Annapurna Circuit · Manaslu Circuit · Annapurna Base Camp Trek · Nepal · Nepal trekking permits · How long is the trail?.

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