Adjusting to Altitude

11:39 a.m. on March 25, 2011 (EDT)
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Getting above 10,000 feet produces altitude sickness (headaches, nausea, general malaise, and at the extreme, HAPE and HACE). There is an article in today's Wall Street Journal about research that is being done on AMS (Acute Mountain Sickness). You may have to be a paid subscriber to the on-line version of the Journal to see the full article, though it may be in the "free" section. It notes that a certain number of people have 6 genetic markers that indicate that these people are more readily adaptable to altitude. About 10 years ago, I participated in a study, and it turns out that I am among the lucky folks. This doesn't mean that those of us with the right genes can be dropped on the summit of Everest, or even a lower peak like Whitney or Rainier without suffering altitude effects, just that we adapt more rapidly. The basic rules for adaptation are (1) climb high, sleep low, (2) when above 10,000 ft, move your sleeping altitude up an average of 1000 ft a day (you can climb 2000 ft during the day, then come back down 1000 ft for your campsite, for example), and (3) if you start getting the headaches, nausea, etc, and especially if you have signs of HAPE or HACE, descend, descend, descend!

There are medications that will aid adaptation for most people. According to the article, acetazolamide (Diamox) and sildenafil (Viagra) work, but can interact badly with other medications and have side effects, like all drugs (Diamox's most infamous side effects are "the tinglies" where your fingers feel like they have fallen asleep, and carbonated beverages taking on a bad taste, most important for climbers being that beer tastes terrible). There are also some drugs that will counteract HACE and HAPE, if they have not progressed too far.

Although not mentioned in the article, a certain percentage of the population is genetically unable to adapt to altitudes over 9000 or 10,000 ft. I know several people in this category, one of whom is my primary care physician (as the insurance company term goes), much to his disappointment, since he and his wife are avid outdoor types, who we see from time to time backcountry skiing below the 8000 foot level.

4:21 p.m. on March 26, 2011 (EDT)
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After years of living above or around 6000 feet in the summers in Jackson Hole then going down to hike in the Grand Canyon, I could always tell like an internal altimeter when hiking out when I got to around 6000 feet because I would start to notice it getting harder to hike even with only a couple thousand feet to go to the rim of the canyon.

6:08 p.m. on March 26, 2011 (EDT)
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Another tip in fighting altitude is remaining fully hydrated.  Dehydration degrades your tolerance considerably.

Ed

12:38 p.m. on March 27, 2011 (EDT)
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Last night I watched "The Wildest Dream" about George Mallory & Andrew Irvine's expedition on Everest and more recently the 1999 expedition to find their bodies where Conrad Akers found Mallory.

After reading Bill's post and the article he linked to I had a much better understanding of altitude sickness. I have had a very basic understanding for a long time, but since I don't exceed 6500 ft where I go I wasn't inclined to learn more.

I must say though that having a deeper understanding increases my respect for mountaineers. I have always enjoyed these types of documentaries so maybe I'll get even more out of them now.

2:22 p.m. on April 10, 2011 (EDT)
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I spent a good portion of my teen years in Leadville, Colorado at around 10,500' or so.  (The remainder at 7,500' outside of Colorado Springs.)  I don't remember any early-on altitude affects.  Recent studies seem to indicate there may be some long term problems.  High School aptitude (and similar) tests of Leadville's graduates show a slight difference from those in lower communities (<6000 feet).  It could be that the level of instruction is different.  Nothing conclusive.

Most who were driving though didn't realize what altitude they were contending with when they jumped out of their vehicles to take in the tourist and other sights.  Most seemed to take the knowledge that they were 2 miles high as a statement of fact other than impending doom.  Most had spent a few days at least in Denver or along the east side.  Now people from near sea level, routinely fly directly into Aspen or are on the high slopes of Mammoth within in hours.  A few severe cases, but for the great majority there are relatively few complain - most brag about it.

Amazingly few passing through or staying in my town had more than some routine complaint.  I suspect they were unaware nor had been hyped about it by other conversations or discussions before they arrived. Then, 50's, AMS was not very well understood nor even known of by the general public.  After all this was not the Himalaya.  There were a few problems with those who were not adapting well, especially the next day.  Most, I suspect, quickly forgot about it or took it in stride.  Very much like the sea level dwelling (most are) hikers in the Sierra.  Many of the east side trail heads start near 10,000' and go uphill quickly.  A good majority of the first timers are now extremely worried of the toll they will face and apprehensive of the horrors of AMS.  Most forget about it as the day progresses.  A few (relatively rare) have problems that require descent and supervision.

I worked part of a summer on Pike's Peak.  Again there were a few that had complaints or more than just a slight head ache or listlessness and out of breath.  There was a device that for a dime or nickel would dispense a minute or so of oxygen into a funnel shaped mask you held over mouth and nose.  I'm not sure that it did at all (I never saw them change the bottle for a fresh full one), but those who used it claimed they felt better and afterward were not affected.  That was mostly a form of acceptance and getting on with it (some would call it denial).  Few stayed more than a few hours anyway and were on their way back down.  Most who came up from 6,000' below (Colorado Springs) in a few hours and spent a night of it on top were affected at least with the usual published minor symptoms when asked about them.

Thousands lined the road up to the summit for the annual racing car hill climb.  I don't remember (as a child) any of those attending being affected - except by some awesome sunburns and unbelievable intoxication.

Although I was fully acclimated to 10,000+ (it takes the better part of 8 months), I still noticed a difference on or around the top of the many 14rs in the area that we did as day hikes or fishing overnights.  We usually associated our lack of energy to the food (lack of or poor quality) we were eating.  Teens will eat anything so long as it fills them up.

3:33 p.m. on April 10, 2011 (EDT)
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The highest I've been climbing is a bit over a mile, but I've been up to about 8500' for my honeymoon. We stayed in a resort on the top of a mountain near South Lake Tahoe.

 

We drove from Sacramento straight there, which is about a 8000' or more difference in altitude if I remember correctly. I had AMS for 3 days, starting on the second day. It wasn't too much fun, but wasn't terrible either. Headache, nausea, and trouble sleeping were my biggest problem. Also, the dry air was just TERRIBLE. Drinking lots helped a great deal, as another poster said above.

 

Trout - I've seen Wildest Dream - it was pretty awesome, but the lead climber who discussed much of the history seemed weird to me, like he was trying to over dramatize many of the points he made. What did you think?

10:10 p.m. on April 10, 2011 (EDT)
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Trout - I've seen Wildest Dream - it was pretty awesome, but the lead climber who discussed much of the history seemed weird to me, like he was trying to over dramatize many of the points he made. What did you think?

I spent my second honeymoon at around 6000 ft. Not high to most of the Trailspace members, I guess, but if you spend most of your time at 1800 ft it's a big deal.

I enjoyed the documentary a lot, but I don't have much knowledge on the subject so I wouldn't know if they were accurate or not.

I did feel some of the narrative was a little dramatized. I don't know if it was a lack of speaking experience, or if it was encouraged by the director, or what, maybe he was just passionate and was trying to convey that. Overall I enjoyed it a lot.

1:17 a.m. on April 11, 2011 (EDT)
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Anytime I'm going to be hiking above 8,000ft I try to make a point of spending the night before camped at the trailhead. It makes a huge difference on how I feel hiking the next day.

9:58 a.m. on April 11, 2011 (EDT)
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I second what Gary C says!  Sleep at the trailhead!  It sounds east but it can help a lot.  I had a salty mountaineer tell me this once.  My kids and I slept at 6,000 ft at the Cold Springs TH at Mt. Adams.  Neither me, my nine or eleven year old noticed anything amiss at the 9K foot Lunch Counter or the 11.5K false summit (blown off the mtn, trying again this Summer). 

We live at about 1,300ft.  Can I say sleeping at the TH saved us? No.  Could it have? Oh yes!

9:51 a.m. on April 12, 2011 (EDT)
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I don't know how true it is because you can always find a research report that supports just about any theory out there but a couple years ago I read one explanning why spending a night at altitude helps so much. They claimed that the mechanism in your body that adjusted for altitude only kicked in durring your sleep. At the very least I assume that it gives your body time to adjust before your physical activity begins.

1:53 p.m. on April 12, 2011 (EDT)
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Hmmm, some misimpressions circulating here. Partly my poor stating of some information and partly leaving stuff out to oversimplify.

1. Some people have some symptoms of AMS by 7000 ft (notably headache, lassitude, some loss of appetite), though the vast majority do not. Many people notice some shortness of breath by 5000 ft, though the vast majority do not, and then only when trying to go as fast as when they are at sea level.

2. Most people can go to 10,000 ft and get along just fine, as long as they take it easy. But pushing it can result in a strong headache, nausea, shortness of breath for the majority of people. A day or two and a night's rest will usually take care of things for most people.

3. A small percentage of the population (about 10%) find it difficult to impossible to acclimatize above 9000-10,000 ft, and a small percentage of those have been known to develop HAPE as low as 9,000 ft (this is rare, and usually then in people with other compromised circulation problems - though people with congestive heart failure have been known to live for years at high altitudes, such as Leadville, that someone mentioned).

4. Most people need acclimatization over several days (the climb high sleep low practice) to work well above 10,000 ft. The need for acclimatization increases with altitude over 10,000 ft.

5. A small percentage of the population acclimatizes well above 15,000 ft, and a still smaller percentage over 18,000 ft (the "half-way" point in the atmosphere as far as air pressure, hence oxygen content per unit volume and the partial pressure of oxygen).Sea level O2 partial pressure is about 6 in.Hg., at 18,000 ft it is about 3 in.Hg.

6. For most people, the oxygen saturation level in the blood drops rapidly with altitude over 5000 ft. At sea level, O2 saturation is typically 97-99% (I am normally at 99%, though for my two recent medical procedures, they measured 100% before putting the oxygen mask on me - through which they also administered something to make me "sleep" - I must have been hyperventilating, and my BP was jumping to 124/62). At 5000 ft, saturation typically drops to 95%, at 10,000 to 90%. (at sea level, if your saturation is below 90%, they will probably want to take you to the emergency room).

7. When you spend time at altitudes above 15,000 ft, your body (for most people) will adjust over time and bring the resting saturation level back up into the 90-95% level (at the 17,000 ft camp on Denali, having climbed gradually up to that altitude and followed a "climb high sleep low" schedule, I typically have measured 95% within the first day or so at that altitude). But I have seen other climbers who were measuring in the mid 80% range, but still were climbing strongly.

8. Physical fitness does not correlate with avoiding AMS, or even HAPE or HACE. Some very fit climbers have succumbed to HAPE and HACE at high altitudes.

1:56 p.m. on April 12, 2011 (EDT)
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Most of the backpacking I do takes me up to 6k, which is small potatoes and nothing that would induce AMS. I do think frequently spending time at that mid elevation helped when I went out to Wyoming. I backpacked in and spent one night in the Shoshone NF at up above 9,000ft, and it didn't seem to effect me at all. I am sure that I would likely have felt it if I hadn't spent the prior 4 days in Dubois at 7,000ft. 

I really look forward to getting out more at higher elevation. Next time I get out there, hopefully this fall, I plan on making time to get out into the Tetons.

9:01 p.m. on April 12, 2011 (EDT)
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My personal experience has been two episodes of what was probably HAPE, which in my case was diagnosed, if I recall correctly, as pneumonia. Both occurred in the same place, La Paz Bolivia, at about the same altitude-between 10.5 and 11.5K about two years apart. Same scenario-flew into La Paz, woke up the next morning so sick I had to be hospitalized for a week or so-on IV and oxygen most of the time.  Other times I flew down there, I was fine, more or less, nothing more than a headache for a bit.

Once you were down there for a while, most people could go up to 15-16K with no problem, me included. Also flew a few times in an unpressurized plane at 18K without too much fuss.

We did keep a small oxygen bottle and mask around the house just in case, as I remember.

On my winter Yosemite trips (missed it this year), I drove from LA to Badger Pass, snowshoed or skied in and set up camp at 7500ft. all in one day with no ill effects at all, except my first trip and that wasn't altitude, it was some kind of food poisoning I got eating in Merced before driving into the park the next day.

10:11 p.m. on April 12, 2011 (EDT)
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My personal experience has been two episodes of what was probably HAPE, which in my case was diagnosed, if I recall correctly, as pneumonia. Both occurred in the same place, La Paz Bolivia, at about the same altitude-between 10.5 and 11.5K about two years apart. Same scenario-flew into La Paz, woke up the next morning so sick I had to be hospitalized for a week or so-on IV and oxygen most of the time.  ..

Before it was really understood, HAPE was often diagnosed as pneumonia. The two have fluid in the lungs in common, with the same "rales" sound when you listen with your ear against the person's back or chest.

4:59 a.m. on April 13, 2011 (EDT)
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The highest I've been climbing is a bit over a mile, but I've been up to about 8500' for my honeymoon... ..

I had AMS for 3 days, starting on the second day. It wasn't too much fun, but wasn't terrible either. Headache, nausea, and trouble sleeping were my biggest problem.

That is AMS alright, but not the kind brought on by altitude.  You sustained what many grooms suffer: Altar Maliase Syndrome.  Lucky for you it passed quickly, some never get over it.

Ed 

2:13 p.m. on April 13, 2011 (EDT)
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I live at about 10-ft above sea-level (Del-Mar-Va Peninsula).   Don't think I have ever been above 6000-ft  (Mt. Mitchell, in The Smokies).   I am VERY concerned about altitude sickness.

Planning hiking in Rockies sometime this year (probably Autumn).   Will heed all the advice I am reading here.

 

 

r2

2:48 p.m. on April 13, 2011 (EDT)
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Acclimatizing for high altitude adventures will be handled in these in the future. It's a chamber for Cyclic Variations in Altitude Conditioning. Check it out. I've used it, with short, controlled exposures simulating atmospheric pressure at 22,000 ft (graduated per session to that point) and it's revolutionary.  

www.cvacsystems.com

4:17 p.m. on April 13, 2011 (EDT)
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hahaha that's too funny ed

11:19 p.m. on April 13, 2011 (EDT)
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We all have different tolerances. I've hiked above 11,000 feet in Colorado with no ill affects. I ran atop Sandia Mountain in Albuquerque, New Mexico, 10,678 feet. A relative of mine had headache, nausea and then vomited. While in Santa Fe, New Mexico, 7,000 feet another relative had a nose bleed. I don't consider myself exceptional. I didn't acclimate for any of the above environments, but acclimatizing is recommended.

4:45 a.m. on April 14, 2011 (EDT)
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I have been pretty high up, yet the worst AMS attack I ever had was at a lowly 8K feet - vomiting and a head that felt like I just smacked it hard on rink ice.  Four aspirin and a 1000 foot descent was all it took to get back to normal.  The most significant correlations to my experiences with AMS are dehydration and fatigue.   As long as I manage these issues and follow the advice Bill describes, I have minimal issues, relative to others on the trail.

Ed

1:02 a.m. on April 21, 2011 (EDT)
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What are the specific guidelines for adjusting to altitude. On a recent trip to Kilimanjaro I relly felt like I was bamboozeled by the whole aclimatezation story. I booked one of the longer routes to be "safe". What I found was that we passed the 10K mark for about 2 hours on the 3rd day of the 7 day trip. We spent the rest of the time under that point. Can any real adjustment take place in this type of situation. I am very much a novice hiker so I anyone can explain in simple term what the general guidlines are it would help me.    

4:03 a.m. on April 21, 2011 (EDT)
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Most people who visit to backpack or ski in Colorado or California come from near sea level and probably don't waste a lot of time between the airport and the trail head or lift line.  Most don't have a significant problem.  Very few complaints (other than the time/money spent and the parties missed) are the ones who stay in Denver and ski during the day at higher altitudes.

A typical worst case scenario would be the person who stayed up all night repacking the pack, had little to eat or drink until they got on the plane and maybe had a couple of alcoholic drinks in celebration and self congratulations; is too excited or stressed out to sleep; is dumped in the airport to find a way with a extremely heavy pack and a few totes because it all wouldn't fit, to get a car, (dang the reservation is lost) and instructions to get to the mountains.  En route, they stop for a fast food greasy, salty meal, and a big bag of potato chips or snacks, a load of soda or beer and they get to their initial destination after 5 hours of driving and eating only to arrive at the trail head they were going use as overnight acclimation in a driving rainstorm.  So they drink the rest of the beer and eat what ever else is handy and enjoy being there finally.  Dehydrated, no sleep, stressed out and tired they will wonder why they don't feel so hot the next morning.

The other extreme are those who have taken a few precautions to make sure they have had plenty of 'good' things to eat and drink, are well hydrated and well rested and fit for the exertion to happen.

Most who visit the altitudes in the Rockies and Sierra have only mild affects usually, a slight rattle in their head when they shake it, a malaise and general lassitude, a noticeable need to breath more often and deeper, and a depressed appetite which may include a woozy stomach. 

Most of these symptoms disappear quickly mainly because they simply forget about it, and forget about being at higher altitude.   Symptoms can definitely be made to appear worse if they are expected to be.

Many - probably the majority -  hardly notice anything other than a little lack of energy and running out of breath easily when at or around 10,000' which many trail heads start or where they may end up for the first night.

Most who do Mt Whitney in a day hike (22miles round trip) are more bothered by the effort than the altitude - except they have to breath more often.   Many who spend the first night at Trail Camp (well above 10,000'), are generally ok when they go to bed, but the next day find they have symptoms.  A rare few have severe problems that mimic a bad flu in many ways and are at high risk.

Being fit doesn't keep you from having affects of not being adjusted to altitude.  It does let you get higher faster (not that good a thing) and it does allow you to do things even if not feeling well - maybe ok.

A few have very uncomfortable symptoms spending the night unacclimatized at 10,000'.  Almost everybody have symptoms after spending the first night of the trip at 14,000'.

The problem is going up hill too fast, sleeping at too high an altitude for your level of adaptation.

For most purposes in the lower 48, so long as you can get back to where you spent the night before, it doesn't matter how high you go during the day.   So either the 14,000' summit attempt from 10,000' or so or just staying at 10,000', you will feel about the same the next day.  Well, except for the sore muscles from too much activity.

But if you already have symptoms, they will only get worse as you get higher.

Take it slow when going above 8,000'.  Above 10,000' if you are the unlucky few, you will not feel good.  For the rest of the world you will be slowed down but not sick.  The longer you take to get higher the fewer new symptoms you will experience. 

As BillS said.  An additional 1000' gain in a day is a good rule of thumb if you are staying out another night.  Most won't do it, because they don't want to blow almost a week for a two night trip.   Sooo, it usually is a compromise and a risk.

If you feel miserable or notice somebody else is, treat the symptoms.  If Ibuprofen or similar doesn't work, going down will fix it.   When you get to a altitude that you feel better, start over going up - just slower this time.

Mosquitoes, freeze dried food and a tent mate with an awesome snore will more than likely be more of a nuisance than will be the altitude.

But treat it as the risk it is and handle it when it comes up.

Read up on it.  Lots of links on the Internet under AMS, altitude sickness, etc.

1:30 p.m. on April 22, 2011 (EDT)
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What are the specific guidelines for adjusting to altitude. On a recent trip to Kilimanjaro I relly felt like I was bamboozeled by the whole aclimatezation story. I booked one of the longer routes to be "safe". What I found was that we passed the 10K mark for about 2 hours on the 3rd day of the 7 day trip. We spent the rest of the time under that point. Can any real adjustment take place in this type of situation. I am very much a novice hiker so I anyone can explain in simple term what the general guidlines are it would help me.    

Since everyone reacts differently, there are no "specific" guidelines. There are some general guidelines, though.

1. "Climb high, sleep low." This means that you move up the mountain in increments, going up 1000 ft or so above your planned sleeping altitude, then descend to your planned camp for the night.

2. "Move your sleeping area up by an average of 1000 ft per day, once above 9000 or 10,000 ft altitude". Most people can come from sea level to sleep the first night at 8000-10,000 ft with only a mild headache, a bit of nausea, and reduced appetite the next morning. This is a bit of AMS, brought on by the normal slower breathing when sleeping, hence reduced oxygen intake. This usually goes away with morning activity and breakfast.

3. "If AMS develops beyond a slight headache, especially to HAPE or HACE, DESCEND, DESCEND, DESCEND by at least 2000 ft, preferably more". This is mostly to get to a higher level of oxygen content (higher partial pressure of oxygen).

You probably spent the first night or two in one of the towns in Tanzania (Moshi?). These are at about 3000 ft, which gives a little acclimatization. But I am not sure what route you would have been on that the 3rd day was the first time you got over 10,000 ft, and the rest of the time lower. Are you sure about the altitudes? How could you have gone to the summit (19,457 ft) if you were under 10,000 ft "the rest of the time"?

The first camp on all the routes is in the 9000 to 10,000 foot range, with the second camp being at 11,000 to 12,000. The Machame route is fairly typical for a 7-day itinerary -

Day 1 Machame Gate (5580) to Machame camp (9900)

Day 2 Machame camp to Shira camp (12,672)

Day 3 Shira with the side loop to Lava Tower (15,000) to Barranca camp (13,035)

Day 4 Barranca up Barranca Wall then down to Karanga Valley (13,500, some stop here overnight) then up to Barafu (15,180 ft)

Day 5 (or 6) Barafu to summit (19,457 ft) then down to Barafu for a couple hours, continuing to Mweka camp (10,230)

Day 6 (or 7) Mweka camp to gate and back to town.

Rongai route is a bit easier, but Kili is considered by many to be rushing things. About 40% of people on the Mweka route turn back, and about 20% on the Machame, due to AMS. Since I am luck enough to adjust rapidly, I was astounded at all the people turning around.

11:16 p.m. on April 24, 2011 (EDT)
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I regularly ski patrol to 9,500 ft. and hike and backpack to 11,000 ft.. My answer, besides good physical conditioning, is to take NO2 tablets. They are nothing more than 8 hour  time-release L-argenine tabs. The amino acid L-arginine , like Viagara and Cialis, create nitric oxide (hence the name) in your bloodstream.

Nitric oxide dialates vessles and capillaries to permit greater blood flow to muscles and especially thelveoli in your lungs. This in turn permits a greater oxygen uptake or "VO2 max".

I get mine at Vitamin world B/C they are less expensive ther than GNC. But they are not a cheap date, in any case.

One will also experience definite AM tumescence the day after taking NO2... :)

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