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Altitude Sickness
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Craig Lewis
(craigl28) - F

Locale: SoCal
Altitude Sickness on 11/01/2007 18:06:10 MDT Print View

I need your expert advice on how aclimate to altitudes above 10,000ft. Last time I BP'd at that level was 30 yrs ago when I was 18 y.o. and in decent shape. Now, I'm in basically the same shape strength-wise, but my cardio is a little less now.
I recall one definite case of hitting a ceiling at 10K before turning back down from bad headache.

Mike Barney
(eaglemb) - F

Locale: AZ, the Great Southwest!
"Altitude Sickness" on 11/01/2007 18:39:01 MDT Print View

I'm aware of a few thing people do in AZ and CO when they head to altitude (10K- 14K) to ward off physiological problems at altitude.

1) Get there 3-5 days early at an intermediate altitude and attempt to adjust. Not everyone has this option.

2) A couple of asprins spread out over the day seems to work for myself and others.

3) There is a prescription drug, Diamox (Acetazolamide), that supposidly allows you to metabolize more oxygen.

4) Stay highly hydrated.

Some or all of these may or may not work for you, but this is what I've heard that works for others.

Good luck,

Bob Bankhead
(wandering_bob) - MLife

Locale: Oregon, USA
Altitude Sickness on 11/01/2007 19:03:15 MDT Print View

See the sections in the Guide to High Altitude Medicine at

This is not something you want to play around with, but neither should you fear it out of ignorance. There are ways around it once you understand and can recognize what you are dealing with.

Diamox is only one of the drugs that can be used, but it's not a panacea, nor does it make you bulletproof. Study that site very carefully.

Let me quote one relevant section:

"The Golden Rules

If you've been paying attention to the tutorial so far, these will be familiar. If there is a nugget of knowledge to take away from this tutorial, here it is:


If you feel unwell at altitude it is altitude illness until proven otherwise.


Never ascend with symptoms of AMS.


If you are getting worse (or have HACE or HAPE), go down at once."

Edited by wandering_bob on 11/01/2007 19:08:30 MDT.

Bob Bankhead
(wandering_bob) - MLife

Locale: Oregon, USA
Altitude Sickness on 11/01/2007 19:12:21 MDT Print View

Another helpful hint:


It is suggested that if possible, you sleep no higher than 1000 feet above your previous night's camp. Climb as high as you like - or can tolerate - during the day, but get back down to a lower altitude to sleep.

Edited by wandering_bob on 11/01/2007 19:15:58 MDT.

Chris Jackson
(chris_jackson) - F
Re: Altitude Sickness on 11/01/2007 23:20:37 MDT Print View

As Bob says, the fastest way to acclimate is to 'climb high, sleep low', elevating your campsite by 1000 ft/day. Sleeping low allows your body to recover properly. If instead you sleep high, you will feel severely fatigued when you awake. Given that you previously experienced a bad headache at 10,000 ft, spend the first night well below this altitude, eg 5,000 or 6,000 ft. Lack of oxygen increases the risk of a heart attack, so if there is any possibility of heart disease then ask your doctor for a physical and maybe a stress test prior to your hiking trip. The good news is that elevating the campsite by 1000 ft/day really works. You'll be able to truly enjoy a headache-free hike!

Peter King
(pking) - MLife

Locale: N. Nevada
Re: Altitude Sickness on 11/02/2007 08:37:56 MDT Print View

1. Both experience and physiology indicate that a high fat diet can exacerbate altitude problems.

2. Overbreathing can help significantly; it mimics one of the adaptations the body makes when acclimatizing. Force yourself to increase the depth and frequency of your breathing, while moving and when you have a headache. One aid to doing this is to link your breathing to your footsteps, finding the appropriate number of breaths per step and using that to regulate your pace.

Craig Lewis
(craigl28) - F

Locale: SoCal
Peak Sun Factor in AMS on 11/02/2007 13:34:27 MDT Print View

Guys, thanks for all that good advice.
My one HMS case was combination of wrong timing sun-wise and no acclimation time. Timing the peak sun as a long rest stop/nap in the shade is probably also part of the AMS prevention until you fully acclimate.

Edited by craigl28 on 11/02/2007 13:39:17 MDT.

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Avoiding altitude sickness on 11/02/2007 17:48:01 MDT Print View

Lots of good advice in this thread. One additional suggestion: Develop and follow a regular program to increase your cardio-vascular fitness. The better your cardio-vascular fitness, the less likely you are to have trouble with AMS. It is not the only consideration, but definitely one of the key ones. If you are starting from scratch, take it easy and realize that it will take time to achieve results, because it is not just a matter of improving heart and lung capacity, but also of laying down denser networks of capillaries in the working muscles and increasing the number and size of energy producing mitochondria in these muscles. This adaptation takes longer. But if you stay with it for at least a year, you should see a marked improvement in your ability to hike comfortably at altitude. You will also build a lot of leg strength in the process. Lots of good books on the subject, BTW. Google 'em up and see what you think. Good luck.

John S.
(jshann) - F
Re: Avoiding altitude sickness on 11/03/2007 04:53:12 MDT Print View

Whether high-altitude illness occurs is determined by:
1. rate of ascent
2. altitude reached
3. altitude at which an affected person sleeps (referred to as the sleeping altitude)
4. individual physiology

Risk factors include:
1. history of high-altitude illness
2. residence at an altitude below 900 m
3. exertion
4. certain preexisting cardiopulmonary conditions

Diverse interactions between genetic factors and the environment most likely explain individual susceptibility.

Physical fitness is not protective against high-altitude illness according to the New England Journal of Medicine paper of 2001, with this reference given (

Tom said,
One additional suggestion: Develop and follow a regular program to increase your cardio-vascular fitness. The better your cardio-vascular fitness, the less likely you are to have trouble with AMS. It is not the only consideration, but definitely one of the key ones.

Edited by jshann on 11/03/2007 04:59:22 MDT.

Brett .
(Brett1234) - F

Locale: CA
Altitude Sickness- one simple preventative measure on 11/03/2007 09:01:05 MDT Print View

I recently led a group of 5 flatlanders to the summit of Fujisan at 3,776m (12,388). From sea level, we stopped on day one and slept at about 10,000 feet. The morning of the summit attempt one party member was weakened, with nausea, a headache, malaise, difficulty talking or performing simple tasks, etc.. classic altitude sickness. I was about to take this individual down when I noticed irregular breathing patterns. We focused on deep, regular breathing, which seemed to increase the saturated oxygen in the blood, because all symptoms were significantly reduced, and the individual summited and descended with the group.
So if conditions are not critical, try that simple technique; no shallow rapid breathing; deep regular breaths with a moment of pressurization when the lungs are full before exhaling.
It worked for this individual on a moderately high peak.

John S.
(jshann) - F
Re: Altitude Sickness- one simple preventative measure on 11/03/2007 10:22:54 MDT Print View

Hi Brett. That difficulty talking and performing simple tasks would have cause me to take that person down. Interesting about the breathing and that person then summiting though.

I don't follow all the studies on this topic, but there must be something out there about breathing routines and their affect on AMS. Stimulating respiration is one of the actions of Diamox.

Edited by jshann on 11/03/2007 10:24:49 MDT.

David Olsen

Locale: Steptoe Butte
pressure breathing on 11/03/2007 11:27:40 MDT Print View

Paul Tree
(Paul_Tree) - F

Locale: Wowwww
breathing at altitude on 11/03/2007 11:35:48 MDT Print View

Peter had a good point #2 above.
I've been on a trip where only my jogging friend got headaches etc ~ 10K'. Hard breathing seemed to help us others.

One thing I sometimes do is: Breathe as hard as you can, then increase the pace to where you don't pass out from hyperventilation. Some people may have a weaker signal telling them to increase oxygen. No idea what you could do while sleeping. Many people have undiagnosed sleep disorders.

Also, on the exhale, constrict the flow of air by mostly closing your mouth, making a blowing or whooshing sound. Supposedly this creates a higher pressure in the lungs and thereby higher oxygenation. Combined with the "rest step" technique frequently. Probably breathing harder gives you more oxygen. Even if it doesn't do anything else, it sure makes you conscious of your breathing.

Checking that link above, looks like it could help if someone is actually getting pneumo.

Edited by Paul_Tree on 11/03/2007 11:49:44 MDT.

(RobertM2S) - M

Locale: Lake Tahoe
HACE? on 11/03/2007 18:21:27 MDT Print View

I'm no expert, but "difficulty talking or performing simple tasks, etc., classic altitude sickness" sounds like it could have been incipient HACE, which I have heard can very quickly deteriorate to coma and death.

John S.
(jshann) - F
Re: HACE? on 11/04/2007 01:54:20 MST Print View

The majority of cases of HACE occur because they continued to ascend while they still had the symptoms of Acute Mountain Sickness.

Signs & Symptoms: Severe AMS plus
1. Change in mentation or the ability to think and solve simple problems
2. Loss of coordination - ataxia, can be subtle but cannot tandem-gait walk
3. Possible hallucinations
4. Drowsiness
5. Coma
6. Cheyne-stokes respirations
7. Signs of increasing Intracranial Pressure (ICP)

Tom Kirchner
(ouzel) - MLife

Locale: Pacific Northwest/Sierra
Re: Re: Avoiding altitude sickness on 11/04/2007 17:53:57 MST Print View

Thanks for providing the reference to the article in the NEJM. I read it several times along with a number of the related articles in the sidebar. Two, including the original article, dismissed endurance training as a protective factor; the others focused on various, more specific factors such as hypoxic ventilatory response, hypoxic cardiac response, arterial O2 saturation, etc. All of them used a target altitude for testing of at least ~4500 meters. A bit of background on my original response is in order. It was based on my personal experience and direct observation of hiking, backpacking, and climbing partners over the last 30 or so years. A number of us have a strong running background, most of us pay a lot of attention to cardio-vascular training, whether it be running or other activities, and most of us suffer very infrequently, if at all, from AMS. Most of our experience, however, is at altitudes in the range of 7000-10000 feet with the occasional foray up to 14000 feet(think Mt Rainier), starting from sea level(Seattle area) and very rapidly, i.e. within 24-30 hours ascending to the target altitude. Such is the nature of weekend climbs in the Pacific Northwest. Dayhikes achieve similar altitudes in a much shorter time. One thing that has stood out is that those most likely to manifest symptoms of AMS do so at the higher end of the abovementioned altitude continuum and are the least cardio-vascularly fit individuals of the bunch. I do not think we are particularly gifted individuals, nor are we all genetic freaks. I do think there is something going on here that has to do with training. A bit of additional data, again anecdotal, to add to the discussion. I had an opportunity to talk with a doctor who went along on an Everest expedition back in the late 80's. He was interested in endurance training as a predictor of success at extreme altitude and found, to his surprise, that it was not those with a marathoning background who were likely to perform well at altitude but, rather, those who excelled at shorter distances, i.e. 5K and 10K. This made a lot of sense to me based on my own experience, both as a runner and in the mountains; marathoners operate almost exclusively well within their aerobic capacity(I am not referring to world class runners here), whereas 5-10K runners are performing at a much higher percentage of VO2 max, often slipping over the anaerobic threshhold in the latter stages of a race. Success is related in both cases to well developed ventilatory capacity and cardiac output to extract the maximum amount of O2 from the atmosphere and deliver it to the working muscles via a dense network of capillaries, but the 5-10K runners encounter conditions closer in one respect to what one experiences at altitude, i.e. O2 shortage. According to the literature on AMS that I have read, low arterial O2 saturation is a major factor associated with AMS, and it seems to make sense to me that an athlete who has trained his/her cardio-vascular system to efficiently extract and deliver O2 in a borderline anaerobic situation has a better chance, not a guarantee by any means, of avoiding AMS. Let me be clear, by the way, that I am not talking about HAPE/HACE-different problem. Nor do I discount the primacy of acclimatization in avoiding AMS. At altitude above 15000 feet, and I have some personal experience there as well, there is no doubt in my mind that proper acclimatization is mandatory if one is to avoid AMS and other more serious problems. What I am saying is that developing a strong cardio-vascular level of fitness can increase your chances of avoiding AMS, especially at the altitudes most of us frequent, with the added benefit of increasing your performance following acclimatization. Along the same lines, a high carb diet, mentioned by a previous poster, makes a whole bunch of sense because glucose (or glucose polymers) carry half the O2 required to oxidize it as part of its molecular structure(C6H12O6 + 6O2 ==> 6CO2 + 6 H2O). Fat and protein have relatively less O2 in their molecular structures and therefore require more O2 from the blood, which is a disadvantage at higher levels of exertion and at higher elevations, especially if one is not fully acclimatized. I have found a high carb diet (in my case Hammer Perpetuem) to be very effective at elevation during the day when I am on the move. With that, I shall retire to the sidelines and enjoy the thread. I hope this isn't the end of it, as it is a subject of considerable importance to anyone who enjoys the high country.

Edited by ouzel on 11/05/2007 14:24:14 MST.

(RobertM2S) - M

Locale: Lake Tahoe
Altitude Sickness on 11/05/2007 16:53:33 MST Print View

For what it’s worth: ScienceDaily (Nov. 2, 2007) — "How can some people live at high altitudes and thrive while others struggle to obtain enough oxygen to function? The answer for Tibetans who live at altitudes around 14,000 feet is increased nitric oxide (NO) levels. High levels of NO circulate in various forms in the blood and produce the physiological mechanisms that cause the increased blood flow that maintains oxygen delivery despite hypoxia--low levels of oxygen in the ambient air and the bloodstream. The combined increase in NO and blood flow levels resulted in double the amount of oxygen delivered to the capillary beds in the Tibetans' arms. In this research, blood flow is determined by the length, number and width of the diameter of blood vessels. These numbers are determined partly by NO, which is a dilator of the vessels and prevents high blood pressure, which would result from increased blood flow in restricted blood vessels. NO also helps in the release of oxygen to tissues." Where is Dr. No when you need him?

John S.
(jshann) - F
Re: Re: Re: Avoiding altitude sickness on 11/05/2007 19:55:21 MST Print View

Another paper about the fitness question...

It seems there was one paper in 1978 (Indian journal) with anecdotal cases suggesting fitness did decrease incidence or severity of AMS.

Dylan Taylor
(nevadas) - F

Locale: California Coast
Re: Altitude Sickness- one simple preventative measure on 11/05/2007 20:11:27 MST Print View

yeah brett, the last factor you note is the most important to diagnosing HACE over severe AMS, according to info i got thru a NOLS wilderness first aid sem. they call the symptom "ataxia"-- it is characterized as being a "loss of coordination." yeah, and what happens from there can be real bad, as noted above. they say patient needs to go down immediatly.

on an anecdotal note-- for whatever thats worth-- i remember a friend of mine getting severe AMS on a trip i did with a group of friends to the east side of the sierras some 15 yrs ago. he was puking, stumbling, gasping for breath. he hiked in to meet a group of us who who been at 10 grand, mas o menos, and he was experiencing all the signs noted above. we didnt know better, and he and the rest of us ended up going over the pass, probably somewhere in the 12s, and sleeping back where we had a base camp (in my traditional backpacking days, ugh). he was better after a day or so. but looking back at that experience, i realize how very lucky we were--sheer naivete. now, anything more than a headache is cause to get down immediately.

forget peakbagging.

Paul Tree
(Paul_Tree) - F

Locale: Wowwww
Decision time on 11/06/2007 13:55:46 MST Print View

My first aid instructor called ataxia "The Umbles" - because you are fumbling, stumbling, mumbling, bumbling, and grumbling.
Hopefully not tumbling.
Last year in the Tahoe Daily Tribune, they said that 1/3 of people coming up to 6000' from sea level have some symptoms of AMS, usually mild pneumo. Many of the hotel guests get a headache the first day.

Edited by Paul_Tree on 11/06/2007 17:17:11 MST.