MY reason for writing this is one or two people liked my answers about the strange world of breathing. I am not a clinician, nor a scientist so beware taking me literally. However some things are self-evident dear Watson.
We breath in a mixture of oxygen (20%) , nitrogen (79%) and a tiny amount of some other gases. But all we want is the oxygen to make our bodies function. But the inert presence of large quantities of nitrogen is important since it actually helps keep our lungs and airways open throughout.
The amount of oxygen we need to function as human beings varies less than you might think - the real difference between say a bass or soprano opera singer and plain old Dicky Woods is that they learn and practice brilliant breathing techniques and I just stay alive. Oh and they can sing and I cannot. No, seriously the actual amounts of oxygen vary little. But it is important to understand that for average daily life one lung would be enough. You couldn't easily run for a bus or hit and sustain top C but you'd live fine. This is called natural redundancy; one lung would be enough if working 100%.
But what does vary the efficiency of your lung machine - the five lobes of the bellows, their complex content of alveoli and capillaries and the muscled ribs and diaphragm which operate it all.
The job of breathing in is to bring quantities of air and its vital oxygen content into those little alveoli. Evolution has fashioned little perforations in the alveoli which allow ONLY oxygen through to enter the blood stream and be carried to all the organs of the body and be used to facilitate life. In the process more carbon dioxide - present in the air only minute amounts - is created and this is taken back to the alveoli and the similar one way perforations allow it out of the blood and into the alveoli ready to be expelled. By the way, oxygen is a rather needy little atom and rarely is found on its own. What we breath if actually O2 because nitrogen is really standoffish and won't play except under high pressure and temperature (hence nasty nitrousoxide (NO2) in engine exhausts).
Anyway in this breathing process much fluid can be generated and this is removed by the activity of the tiny cilia which line the even more microscopic (ain't it all incredible?) of our bronchi. Or not in the case of one like me with 'the bronch'' . And thus enter the world as, sorry about this, snot!
Now how well you breath is clearly affected by many things and as we COPD folk learn, many are within our control. But some are not. And this is where it gets interesting, to me anyway.
The air has many properties. At the basic level it contains about 20% oxygen which makes our bodies work. Another near 80% is nitrogen which does not do much at all with anything - its inert and as I( said forms the bulk that ensures we have something to inhale and exhale; it 'delivers' the oxygen and removes the carbon dioxide. There is a minute trace of carbon dioxide already, slightly more of argon (a noble gas which is even less sociable then nitrogen) and a few utterly minute traces of other stuff like helium, hydrogen etc.
And water vapour - in varying quantities.
I bet most of us COPD folk dread days of high humidity. Of course we do. Water vapour is very dense, makes breathing harder and reduces our ability take in and process oxygen. For me any humidity above 70% starts to affect my breathing. I do not need my gadgets to tell me what the humidity actually is - I can guess the moment I wake. 90% plus means a very bad day - and the weather tends to match!
What to do then. Well there are a few things. I reach immediately for my salbutamol and take a couple of puffs and make sure I have it with me all day. I lie quietly and breath in (nose) out (mouth) using the picture on the wall trick to ensure regulation . Then I do some 'pursed lip' breathing - it helps to expell any carbon dioxide lingering due to the bronch. Then I switch to diaphragm breathing using the same regulatory trick and pursed lips. Then both ribs and diaphragm. About sixe of each.
A note re carbon dioxide – some people are what are called 'retainers' (I am one such) and this means they have a tendency to retain carbon dioxide in their alveoli. And this is very unhelpful to breathing since it stops oxygen even reaching the alveoli! (It is important not to confuse carbon dioxide with carbon monoxide - this latter is deadly, odourless and the result of bad combustion).
So, anyway, I also resign myself to having to use my oxygen for at least the full 15 hours prescribed (ugh!").
But there is more. If you feel you have mucus blocking your airways or your sinuses (they are part of the pressure balancing process) or you suffer any level of 'bronch' getting it out may be difficult but will help your breathing. So stand up (gravity helps here!) and do some snorting. No seriously. I call it rasping but the object is to vibrate your airways during breathing. Some call it 'herr' breathing after the sound it makes.
The idea is that if you can shake up the mucus it will make it smaller and easier for your airways to transport it. And thus, after a few snorts, I generally find I can produce a useful cough or two and clear some of the muck of the night. It will feel as if only the upper bronchus is affected but in fact the vibration can reach down a decent way.
So, it 90% humidity and a poor breathing day is in prospect, can it get any worse. Of course it can – this is COPD!
Temperature matters a lot – cold air is hard to breath in and your respiratory equipment does not function so well below say 10C. So wear a scarf, use it as a muffler (not one that leaks fluff!) and try to be sure to breath in through your nose giving your sinuses and the pathways a decent chance to warm the air before it hits your (minute remember) airways and alveoli and they shrivel up in horror!
But heat doesn't help either. I find anything above about 27C can make life difficult. Why? Well warm air is thinner than cool air and so every breath will carry a couple of per cent less oxygen. Now to a 90% FEV breather 2% means nothing at all. But down here at 30% FEV it is one fifteenth of my air – or nearly SIX pre cent! So what happens? Your body demand you breath faster.; But we have poor equipment and that will mean s shallower – its Catch 22 time!
This may be the first time it is best NOT listen to your body. Stop doing anything at all. Especially talking. Take the weight off your feet and find some way to rest your upper body without collapsing your lungs (I call it tripodding) and start to breath in at a nice steady pace counting one...two...three. Then out one...two...three...four...five. And repeat. Or find something like a panoramic picture and follow the shape ... up, along, down, along, up.
Can it get even worse? I think so I fear. Have you ever heard of ozone? Yes its the stuff produced in the upper atmosphere and its not very nice. It is rarely found at sea level but at the seaside it can occur. Violent wave action and specific weather conditions can combine it seems to produce something a bit like ozone. Bit of technical stuff here. Oxygen is O and one atom is O but as I said, oxygen is a right tart and cannot get about much on its own. It demands company and in the absence of anything ese it marches about in pairs – what we breath is O2. Ozone is O3 and we cannot breath it as it is the wrong shape for our alveoli (plus it is poisonous anyway). It does smell nice which is often why people like being beside the seaside. If only they knew...
Anyway, sometimes by the seaside you can get traces of ozone, coupled with high humidity (natch, you are by the sea) and some temperature and pressure effects which combine to ensure that your COPD day by the seaside was not much fun at all.
So what's my theory in all this? Well I think that knowing more about how you breath and what you breath and why is key to coping with COPD etc. And some of these effects will be dismissed because to fit and healthy people most of them have a minute effect. It's just that the fit and healthy, breathing lungfuls of air have not the foggiest idea why a drop in the ocean is a kick in the guts to us!
SIDEBAR: About me and my lungs....
Sorry about this but I am a little short of breath today...
THERE was a time when I used to say that with a wry smile. Sadly there was also a high chance that a fag was hanging out of my mouth at the time.
Today of course as a severe COPD victim I am permanently short of breath. In fact now 79 I have no idea what my 'lung age' is. Ten years ago a doctor with a dry turn of humour informed me "You have the lungs of a 95 year-old Mr Woods". I laughed but noted that he did not.
And so I now have a cocktail of ailments and absorb an unwarranted numbers of pills and inhalers and ambulatory oxygen every day. I started out with childhood asthma but that cleared to leave me a fairly healthy adulthood. I was fortunate to retire at 60 and we set off to tour the world in a motorhome (well Europe anyway) but by Christmas 2003 I was back in blighty not at all well. I seemed to recover but it was an illusion and in April 2004 they gave me three months to live without treatment. Acute Myeloid Leukemia. Two varieties, one nasty the other aggressive; you choose. Anyway two sessions of chemo ended with one nearly killing me so we switched to using my brother's T-cells to deliver a new immune system via a bone marrow transplant. Thanks Rog.
And recovery began, with two doses of pneumonia (caused by the desired but dangerous Graft Versus Host Disease - do not ask; take too long). But given my smoking, an incident caused by Hitler in 1943 and that childhood asthma my breathing was not good.
2006 and a biopsy revealed emphysema and a side dish of bronchiectasis, probably the result of scarring during the pneumonia episodes. (my theory, btw). And so it all began.
Eating disorder and breathing issues
Pneumonia recovery / Bronchiectasis - what is what? Questions! Thank you 
Trying to get diagnosis for what you know you have
Dysfunctional breathing.
Anoro Ellipta - have you had side effects
