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Hi everyone,

I know that altitude has been covered before, but my question is slightly different.

I'm planning a trip to a place which is at 3500m above sea level - and that's before I've set foot on a mountain. I had googled the subject pretty extensively, and seemed to come up with positive results - even the BMJ says 'asthmatics do well at altitude' as there are generally less allergens around.

However... my doctor is concerned what would happen to my oxygen levels if I had an attack where there was already substantially less oxygen that normal. Nothing on the internet had mentioned this very logical worry!

He explained the shape of the hemoglobin saturation curve, and how it suddenly drops off - so to start at lower oxygen, I'd be far nearer the drop-off point.

A fantastic website called has explained quite a lot about how altitude affects our blood gases, but is anyone able to add any information - scientific or personal - about what could happen during an asthma attack at altitude.

At 3500m above sea level, there is 66% amount of oxygen as of at sea level, and your lungs will be working twice as hard. However at 2500m, where someone is unlikely to get symptoms of altitude sickness, there is 74% of oxygen available, so although 74% sounds very low, it isn't that bad really. If I were to trek to 6000m, there would be 48% of oxygen around. A fit healthy person on the top of Kilimanjaro at 5895m will have sats around 94. At 7135m (the base of a mountain in the area I'm going to - don't worry, I wont do it) someones sats would be at 73% at rest.

One final question - has anyone been at or over 3500m? Were you confident that you'd recognise the difference between breathlessness from asthma and altitude-related-illness which can be very serious? (Clearly asthma is very serious, but if you leave altitude illness alone and keep going up, you're in big trouble).

Clearly I'm planning a foolish trip, and I recognise that there is an unnecessarily high risk of problems by putting myself in that situation, and I understand that my doctor does not recommend it. But I'm also a headstrong person, and I want to go to this area more than anywhere else in the world. I understand that no one on this forum is likely to advise me to go, but can anyone offer any advice or info?

Thanks v much. C x

14 Replies

Were areyou going?

Julie Tullis was a Himalayan mountaineer who got up everest or K2 and she had asthma. HAPE &HACE are totally indiscriminate. very fit people can be severely affected whereas unfit ones canbe ok. Ther aws a series on BBC1 calles Everest Doctors ?? a few months ago.

go for it and good luck! :-)



Hi C,

I hope this helps a little to answer some of your questions:

I’ve skied at over 3,600m on about 3 or 4 separate occasions mainly in Tignes (French Alpes) At this altitude most of the party I was with (asthmatics and non asthmatics) felt breathless, although that might have had something to do with lagging the skis around too!

Interestingly I actually was less bothered by the altitude than by my non asthmatic parents. Saying that I am 24 and they are in their 50s. This may also be due to the fact that I’m probably less likely to find breathlessness distressing being asthmatic.

I had no problems with my asthma becoming worse at altitude. I found it relatively easy to distinguish between altitude associated breathlessness and my asthma as I found that when the altitude did effect me I just felt breathless rather than tight chested and didn’t cough as I usually do when my asthma is problematic. I also found the fact that everyone else around me seemed to be gasping reassuring!

I kept a closer eye on my peak flows while I was out there too, I figured that a drop in peak flow probably indicated that my asthma was worsening whereas feeling breathless with a normal peak flow was more likely to be altitude related.

Hope this helps,

Go for it,



Thanks Kate and ST,

I'm aware that my chances of actually having an attack at altitude are not necessarily any higher than at sea level, but what my Doc brought up was what would happen to have an attack when the amount of oxygen would be sub-optimal in the first place.

I've spoken to a friend who went to Everest base camp, (fit, healthy, young), his SATS at base camp were in the 70s. (But his body would have acclimatised, and his blood would have more hemoglobin, so its not as bad as it sounds!). That makes me think that I'd be OK...

I'm spending next week trekking at 2500m, so if that goes OK, maybe I can risk it.

One final thing - spend 1 or 2 days going by bus and ending up at destination at 3500m (but this involves the highest road in the world, in India, where anything is possible, and goes up to 5000m at parts). Or fly straight to 3500m, avoid the risk of getting stuck at 5000m, but don't get any acclimatisation at all. As much as I want to go by bus, I think fly...

C x


I have very similar experiences to ST! Infact I have even been skiing in Tignes as well. I know from previous experience that I cope well with altitude. I climbed Mount Kenya about 7 years ago and was fine. Thinking about it myself and Esther (another asthmatic) found the slight feeling of breathlessness much much less distressing than anyone else did.

My advice would be to take care, swot up on the symptoms of altitude sickness and what to do if you develop symptoms (and make sure everyone else in your party does too). Also good travel insurance and make sure you find out whether you need to take out 'membership' of the Flying Doctors (one of the best $50 I spent!- in Kenya they won't rescue you unless you have paid your subscription previously). It it was me I would worry more about the dust and how far you are from a hospital.


Thank you very much for your support, Kate, ST and Bryony. I got a bit freaked out by my doc's reaction to my plan, this has made me feel a lot better.

I am very, very aware of how isolated I will be - a helicopter rescue in the Himalayas involves a minimum wait of 24hrs, and I am going to a particularly isolated part, where helicopter rescue is pretty unlikely. But I'm armed with epi-pens, and insured up to 6000m.



Hi C!

Glad you got some slightly more reasuring and more useful replies - mine was written in a slightly hypoxic state! LOL.

Refering back to the 'Everest doctors' they were dooing Arterial blood gasses on people at hight altitudes, very near the top of everest 29,000ft, and they had levels of 40 % I think!

As others have said here, they haven't had that much of a problem.

I have asked my friend who is a specialist healthcare librarian if she can dig out some research - will be next week now though.


PS my Mum suddenly discovered her altitude insurance was a bit short - sorted now, though I don't think she will be doing 15,000 ft again! 3000m I think.


Hi C,

From personal experience of climbing Mount Kilimanjaro,(5,800m) Mont Blanc (4,800m), trekking in the Himalayas, and climbing the highest ‘peaks’ in the UK, all with a peak flow ranging from 400 – 130 average the most noticeably warning symptom has been that of an increase in breathlessness re asthma probs.

I used to wheeze loudly too and believed this was more worrying a symptom than breathlessness. Not at all though. I’m often reminded of the time, - LONG time ago - when I kept everyone awake through the night because of loud wheezing and then got up - in the very early morning – to run off and complete an ultra distance mountain/fell race in an OK time. I was accused of using race tactics! My respiratory doc told me that wheezing will disappear after the airways constrict to a point where there isn’t enough space to make this sound happen. So if you are wheezing you are OKish, although should never be tested without access to emergency care, and especially when half way up a mountain!

The difference between SATS and PF’s is an interesting one. Your young fit non asthmatic friend’s lungs, not to mention other organs, could probably cope with short term, relatively speaking, lack of oxygen, precisely because his body had become acclimatised to high altitudes. (I think you may have answered your main worry here?) Some types of asthma and asthmatics can become used to a lack of ‘peak’ oxygen flow, hence the reason why particular asthma groups experience dramatic drops in peakflow, but not echoed by lowering of SATS to a similar worrying level.. The problem is that any unexpected trigger like cold air, - always a severe trigger for me – will have an eventual effect on SATS. An unprepared for trigger is NOT the icing on the cake you need at high altitude.

As has already been explained breathlessness can occur because of altitude sickness. In this respect I’ve been incredibly lucky and not suffered from this problem. I can well remember the time, ANOTHER long long time ago (still living on past glories!) when trekking in the Himalayas with a close friend who was far more fit than me. He'd competed in the Ironman Triathlon, did lots of low level climbing, ultra distance running etc) and NO asthma, but who suffered from severe altitude sickness and an even more stubborn ‘can do’ attitude than me. (He had to go down to an altitude that would allow him to re-aclimatise in the end, - bit like diving in reverse – and spent an extra week recovering before starting again.)

I’ve always been able to distinguish between ‘normal’ asthma breathlessness and EIA breathlessness. The former does not improve re symptoms, and the latter does with medication and a very slow warm-up. Again external triggers like very cold dry air can make the difference between being able to continue or not if appropriate meds haven’t been taken before exercise.

You could apply the ‘very slow warm-up’ analogy with your forthcoming trek and mountaineering, especially in relation to a potential problem with altitude. On the other hand you could take a chance… but you need to weigh up the cost/benefit ‘costs’ of using this approach. A SWOT analysis has helped me come to term with decisions that conflict against my normal ‘ let’s have a go’ beliefs in the past and present.

On a practical level, ensuring you have all your normal meds times two close at hand, AND that all other people in your group carry the same medication will help. I don’t travel anywhere these days without a small nebuliser and two weeks supply of pred in addition to other asthma meds. I also give traveling companions the same inhalers. After experiencing a situation a few years ago when my bag – containing all meds - was stolen at a remote airfield in China, I decided it was time to plan ahead for unexpected events!

It might be worth talking to your doc if you have a significant allergy component to your asthma about the prophylactic benefit of taking a short course of oral steroids before your trip, even more so if your asthma is unstable or brittle.

A short course of oral steroids can also help the body acclimatise to altitude sickness problems as well.

I’ve included a few links that may be of use or interest.

Although I’m well past being able to gallivant up Mont Blanc and similar I’m so glad I managed to do so and can at least enjoy the photos, memories, laughs, and fears.

Good luck on your expedition and good for you for having the determination to have a go!




Hi C,

Another daring adventure planned, by the sound of it! I do hope it all goes well.

I don't have anything other than the most basic theoretical knowledge of altitude medicine, and anyway all of that has been more than amply answered by Mia, ST and the others. I have never been at altitude (well, never higher than the top of Snowdon at about 1000m!) and am never likely to, so I can't offer you any direct advice.

I would imagine, though, that the effect of being in an environment that has low oxygen levels, and having low sats to start off with, will put you in a similar position to that of many of us who have chronic airflow obstruction and borderline low sats even when 'well'. Essentially, you are starting off from a lower baseline and any deterioration will therefore take you down to critical levels sooner. As your doctor showed you on the oxygen dissociation curve (here: - if anyone is interested) there is a 'shoulder' in the curve at which a small decrease in sats can lead to a sharp decrease in your pO2, the partial pressure of oxygen in the blood, which reflects the amount of oxygen available to your organs. The 'shoulder' in the curve is normally around 90 - 92% (which is why doctors get concerned when your sats drop below this) but if you are already functioning on sats lower than this, for whatever reason, obviously this leaves you with a lot less 'room to manoeuvre'. There are some compensatory mechanisms which will come in at altitude to shift the curve to the right, so that your pO2 will be higher for any given level of oxygen sats - these mechanisms take a while to kick in, some of them developing over hours, and some taking days or weeks.

The main thing I find, in my analogous situation of having borderline oxygen sats at rest at sea level, is that if I do then go on to have an asthma attack, my sats will drop very quickly to a level where things become quite difficult. Over the last year or so since I have developed this problem, I have found that even quite a mild asthma attack can leave me blue and with low sats, unless I resort to using oxygen, which I am having to do increasingly. The main problem with this desaturation during even fairly mild attacks is that it impairs my judgement about what treatment I might need, so that I have found myself sitting at home thinking that I am okay when I really need to be getting myself to hospital. I can imagine this being an issue if you were to have an attack at altitude.

I think you are right that there is no real reason to think you are more susceptible to have an attack at altitude, if your asthma is mild or moderate and is reasonably well controlled (more severe asthmatics might find themselves triggered purely by altitude, as they will probably have borderline respiratory function anyway, and the extra work they are having to do to breath harder could trigger bronchospasm in twitchy airways, but provided your airways are not too twitchy, you shouldn't have this problem). However, I think you have to be aware that if you do have an attack a) you may deteriorate to a dangerous level of hypoxia more quickly than you would normally expect to do; and b) that this hypoxia may very rapidly impair your ability to make good judgements, including your ability to judge how unwell you are and whether you need to seek help.

I think the possible way around this is to make sure that your fellow travellers are very well aware of your health issues, and that they are well versed in what to do if you do have an attack. I would strongly recommend erring on the side of extreme caution if you do have problems, and starting extra medication/seeking help sooner rather than later. It would also be a good idea to be guided closely by your peak flows, as well as by how you feel, as these will be more objective; although of course it's never wise to base your management purely on peak flows, as they can be misleading in both directions.

The relationship between peak flow and sats is interesting, and you cannot really predict one from the other. Most asthmatics who are reasonably well controlled will have normal sats even at quite low peak flows, as most people have a great deal of respiratory reserve. Low sats is therefore usually a late sign in an asthma attack, and will only be seen when the peak flow is very low during a severe attack. This is not true, however, for the group of us mentioned above who have chronic airflow limitation or borderline respiratory function at the best of times, and equally, it may not be true for you at altitude, as you will be in this borderline situation.

It's not quite true to say that if you are wheezing, you are OKish - whilst most people do become silent chested, without any wheeze, when they are having a severe attack, it's not a universal rule. I have certainly seen people who have loud wheeze and are having a life-threatening attack when assessed on the basis of blood gases, etc. I certainly would not assume, when you are on your trek, that if you are wheezing, you are alright. In fact, with what I have mentioned regarding you coming from a lower baseline and potentially going off more quickly, I think you should assume that even the relatively mild bronchospasm that's usually associated with loud, low-pitched wheezing could potentially cause a dangerous drop in sats. It's also true to say that if you are having an attack and do develop a silent chest, and are feeling very breathless and unwell, and are blue, but are not wheezing, this is a very dangerous sign. In this context, that would be suggestive either of a severe asthma attack or of severe altitude sickness, both of which are potentially serious.

I hope this makes things a little clearer. As I said, my suppositions aren't derived from any direct knowledge of mountain medicine, but from my knowledge of respiratory physiology and how the body behaves in situations where reserves are low, for whatever reason.

I hope I haven't put you off or worried you too much. I have to say I am quite worried by the idea of you attempting this expedition! Clearly, though, it is something that you very much want to do, and you seem well versed in the potential risks and dangers, so I will not try and dissuade you - I have the feeling I wouldn't be successful! I do admire you for wanting to try to do this, at the same time as thinking you are slightly fool-hardy!

Do let us know how it goes, I hope all goes according to plan

Take care

Em H


You are right EmH, ANY wheezing should be taken seriously…

Lesson learnt!

*shuffles off to the naughty step to see if there's any room left* :)


I know that I may well be talking out of my posterior here - but at my worse I am advised not to fly - due to the altitude!

Not sure though if this adds anything to the thread!

Enjoy your holidays - have all your meds with you!


Hi guys,

Thank you so much everyone for your informative replies.

I've just come back from 2 weeks away, 1 week which was spent in mountains (max 2500m). I cant believe how well I felt - I walked 70Km with a 22kg bag (very, very slowly!). Only on one day did I feel really pretty rubbish, 2 OKish days, and the rest were fine. Infact on my second day I was walking up a mountain, and I suddenly realised that it was not any effort to breathe at all - I cant remember a time when it felt so easy to breathe. And I was walking up a mountain! Mountain air is clearly good for me... the cities were tough.

So I'm feeling a lot more positive about my next trip, and will go back to my doc with more info, and hope he wont worry as much!

Thanks again guys, x


Hi C,

I'm so glad you had a good time, it's very interesting what you say about mountain air. I just need a mountain that I can get up with no physical effort (train up Snowdon?!) and is within a safe (ie close) distance of a proper hospital, then I think I'll give it a try too! Seriously, before I developed brittle asthma I was a very keen backpacker - I remember vividly doing my Gold Duke of Edinburgh on the Isle of Arran at the age of 17, 50 miles in four days over some pretty rough terrain. It was an amazing experience that I look back on very fondly. I had fairly bad (although not brittle) asthma at the time, and you're right, it was pretty good in that mountain air!

I hope your success story will inspire other people to take to the mountains and push the limits - within what is safe, of course!

Take care

Em H


Congratulations C and well done.Aim for the stars - metaphorically speaking - AND with a little forward planning!MiaXXXXX


Congratulations C and well done.Aim for the stars - metaphorically speaking - AND with a little forward planning!MiaXXXXX


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