This page is a dump for my research in the lead up to a self-guided trekking trip to Nepal. It's on the web in case it's of any use to anyone else planning something similar.
A summary of interesting/important health advice. My primary sources of information are:
- USARIEM Thermal & Mountain Medicine Division - specifically their Altitude Acclimatization Guide. = Ref#1
- The High Altitude Medicine Handbook by Pollard, A. J. & Murdoch, D. R. = Ref#2
I am not a doctor. Before relying on any of the following information, please discuss it with your health professional.
The effects of altitude on the body are due to reduced oxygen density (less oxygen per breath) and reduced pressure (impaired ability to absorb/transport oxygen via lungs to blood) (Ref#1, p1).
Acclimatization: happens over time at altitude, and is crucial for the avoidance of AMS (Ref#1, p1); fitness level has no impact on speed of acclimatization (Ref#2, p8); acclimatization is most safely acquired by living at between 1500m-2500m for 3+ days (ideally 7 days) before ascending higher (Ref#1, p8); acclimatization at any given altitude for 3 days provides significant protection against AMS during a rapid ascent (< 6 hrs) up to 1000m above the staging altitude (Ref#1, p8); 'slow ascent profile' acclimatization (150m-300m per day, plus a non-ascent day every 2-4 days) is an (inferior) alternative to a proper, 'staged' acclimatization (Ref#1, p9-10); acclimatization is rapidly lost upon descent (Ref#1, p10; Ref#2, p5); 'training' in a hypobaric chamber prior to your trip is probably a waste of time/money, as the requirements for a real benefit are well beyond what most people can commit to, and are rapidly lost (Ref#1, p11-12; Ref#2, p5).
AMS: "is a short-lived (2-7 days) illness similar to an alcoholic hangover" (Ref#1, p3); "sustained physical exertion early in the altitude exposure substantially increases AMS incidence and severity" (Ref#1, p3). The best treatment for AMS is descent - do not re-ascend until symptoms have passed. It should go without saying that further ascent whilst experiencing AMS greatly increases your chances of death by HAPE/HACE. It is worth noting that untreated HAPE/HACE can progress to coma and death in 12 hrs or less (Ref#1, p4) - don't wait until the morning to do something.
Acetazolamide (Diamox®): can be used to hasten the acclimatization process. It is, however, a significant performance disenhancer (Ref#1, p3). It could be argued that it is most usefully taken the evening before, and during the day of, a rest/acclimatization day - not during a trekking day. Acetazolamide can be used to reduce the severity of the symptoms of AMS, but should always be used in addition to rest/descent, and never as a treatment to facilitate further ascent (Ref#1, p3).
"Many choose to use regular drug prophylaxis against AMS, although it should be emphasized that careful planning to incorporate regular rest days and to avoid rapid ascents usually obviates the need for the use of drugs" (Ref#2, p11).
Acclimatization involves significant changes to your blood/circulatory system. Individuals exposed to altitude should maintain an iron-rich diet and/or consider taking an iron supplement (Ref#1, p7).
You can expect your body to develop an increased preference for carbohydrate at altitude, due to changes in metabolic processes (Ref#1, p7; Ref#2, p65-66). A diet high in carbohydrate at altitude will stimulate ventilation and thus improve blood oxygenation (Ref#1, p13).
"Maintaining adequate hydration levels and primarily consuming carbohydrates can improve physical performance and possibly decrease altitude illness susceptibility" (Ref#1, p13). Dehydration is exacerbated by hypoxia and/or acetazolamide.
AIPE - swelling of the face/extremities - can be treated with salt restriction and acetazolamide (p64). Reducing salt and protein intake probably assists your hard-working kidneys during acclimatization too.
See the Centers for Disease Control and Prevention page for Nepal for the latest advice, and enhance it with reference to your home country's advice.
In summary, the CDC recommends ensuring you have up-to-date 'routine' vaccinations (including Measles-Mumps-Rubella (MMR) vaccine, Diphtheria-Tetanus-Pertussis vaccine, Varicella (Chickenpox) vaccine, Polio vaccine, and your yearly 'flu shot), as well as for Hepatitis A and Typhoid. Some people, destinations, and times-of-year have additional recommendations - see their page for more.
Proposed altitude plan for the '3 Passes' route. Purpose is to identify legs that require significant ascent (suggesting a rest/acclimatization day should follow), and, perhaps more importantly, legs that result in a 'high' (150m+) or 'risky' (300m+) 3-day average ascent (based on 3-day acclimatization 'rule' from Health section).
Key for table: blue = no ascent; green = < 150m ascent (= OK); orange = < 300m ascent (= high); red = 300m+ ascent (= risky).
The most obvious thing to call out in the plan as it stands is the 'risky' 3-day average ascent to Tengboche that is followed by more ascent the next day - this strongly suggests an additional rest/acclimatization day in Tengboche.
|Overnight Stop||Altitude (m)||Delta (m)||3-day Average Delta (m)||Bed Count**|
**Bed count data (i.e. the total number of trekker beds available) was extracted from the slightly strange Trekker Planner website - it is unclear how old this data is. Assuming it's in any way factual, it's an interesting reference to see if your visit will coincide with >100% occupancy (e.g. Gorak Shep in October).
This (Nepal AR) looks brilliant - looking forward to trying this out...
December Weather Data
|Place||Rain (mm)||C° avg||C° min||C° max|
|Gorak Shep (5160m)||3||-8.9||-17.8||0.0|
|Namche Bazaar (3440m)||7||0.5||-6.5||7.6|
- Everest Base Camp / 3 Passes
- Waymarked Trails: 3 Passes
- Nepal Trekking Tips
- Great Himalaya Trail
- KEEP Nepal
- TIMS CMS
- Trekker Planner
- Nepal trek gear discussion
- Trekking Agencies Association of Nepal (TAAN)
- Trekking from Jiri to Namche Bazaar
- Jiri Gokyo EBC Trek
- Guide to Everest Base Camp Trek without any flights
- Book: Trailblazer Guide Books
- Book: Trekking in the Everest Region - New edition (6) due Q2, 2017
- Book: Nepal Trekking and the Great Himalaya Trail
- Book: Great Himalaya Trail
So, How Did It Go?See Nepal: Jiri - 3HPs - Jiri...
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