How to breathe?

I might like some advice about breathing. A doctor implied that I'm not very good at breathing: i.e. that I have "central sleep apnea" which probably means that the part of the brain-stem that controls breathing doesn't breathe/trigger enough, so I go for 30 to (while I'm asleep) 90 seconds between breaths, and don't get enough oxygen. The existing question that most closely matches this one, that I found, was [Breath getting shorter and shorter](https://buddhism.stackexchange.com/q/8953/254) . I don't understand the answer to that question (especially the answer's saying, "you have to switch to sensations" – what else is there but sensations?). I downloaded the manual about [Anapanasati](https://campuslink.okstate.edu/organization/buddhist-student-association/DocumentLibrary/View/234593) which that answer recommended, and I hope I get a chance to read it, but it might be useful to read some other shorter/different answer of yours here. So, some specific questions: 1. An instruction about "how to breathe when meditating" might include "breathe naturally". I find that if I "breathe naturally" then: - My breathing gets shallow and then stops for a few seconds. - I wait a bit, thinking "I'm not breathing. But I shouldn't force my breathing, I'm supposed to wait for it to breathe naturally. So I'll wait until my next breath. Waiting. Waiting." - (My oxygenation depletes, which seems to manifest as a slight loss of consciousness, e.g. I'm no longer aware of what I'm seeing and/or of what I'm thinking) - My next moment of consciousness/lucidity is that I'm aware than I am in the process of taking my next breath. When I'm awake this period of 'unconsciousness' is probably (I guess) no more than half a second (though the period between breaths may be several seconds), and only happens while I'm physically at rest (not physically exercising) and emotionally dull (I think I keep a relatively lively interest when I'm driving a car for example). **Questions**: - Does that sound normal? - Is it abnormal/pathological and e.g. a symptom of "central apnea"? - Am I interpreting "breathe naturally" a bit too literally: should I instead, for example, begin to inhale again as soon as I'm aware that I'm not breathing (i.e. that I am between breaths, or that my previous breath has finished)? Should I be trying to breath [continuously not just continually](http://dictionary.reference.com/help/faq/language/g05.html) ? I guess the thing with driving is that I'm not concentrated on / conscious of my breathing: instead, what I'm conscious of is my level of alertness and how well I'm seeing (how good my sight is), and so I suppose I unconsciously breathe (regularly enough) in order to maintain that level. 2. In the comments under [this question](https://buddhism.stackexchange.com/q/3870/254) there are a couple of comments about the diaphragm: > - I disagree. There is a reason why diaphragm works better -- it is a gateway to the emotional mind, so-called seventh consciousness. > - I also think the diaphragm region is better, but more so because the movement of the abdomen is much easier for a beginner mediator to discern. **Can you tell me** something (that I don't already know – you can assume I only/already have high-school-level biology) **about the *diaphragm***, and/or about the "so-called ***seventh consciousness***"? The 'Anapanasati manual' which I reference above barely mentions "diaphragm" nor even "abdomen". 3. Watching a video of someone I notice **that they appear to 'sniff' occasionally** while they're speaking. If I try to do the same, experimentally, do I experience a mild feeling of bliss? Either from the sudden intake of oxygen, or the motion of air through the nose, or from having triggered/activated the diaphragm to implement the sniff? Is there something I should know about that slightly implosive way of breathing, and/or activating of the diaphragm? What I called 'bliss' might be increased alertness or awareness (or sensory input). 4. Is there some **written text** about 'how to breathe' that you recommend? 5. FYI some activities that I find relatively pleasurable are bicycling (e.g. fast or up-hill), the Tai Chi "first form", and singing (in a choir), all of which involve **continuous and/or controlled breathing**. How should this contrast with some vague instruction to "breathe naturally" which I don't understand and don't seem to enjoy much? Is it possible (and/or desirable) to learn to breathe more consciously (or regularly) while still using the brain for other purposes?