Let me begin by making some general observations about what happens when people get acupuncture.
First of all, for the vast majority of people acupuncture is extremely relaxing. Most people fall asleep. The sleep one experiences with acupuncture also tends to be extraordinarily restful and rejuvinative.
This is not everyone's experience of acupuncture, but it does tend to be the most common. It is as if acupuncture causes the body to shift from a more heightened, 'sympathetic' state, to more of a relaxed, 'parasympathetic' state. I personally think it is in this state that the bodies finds its balance.
So there seems to be this kind of general effect with acupuncture. The only people I've heard dare to say that the effect of acupuncture is general is a group of practitioners who call what they do 'biomedical acupuncture'. While I don't know that I agree with all of what the practitioners of so-called biomedical acupuncture espouse (they are pretty much completely dismissive of traditional Chinese medical theory), I do agree that the effect of acupuncture is in some broad sense general.
I personally don't think saying this diminishes or minimizes acupuncture in any way. I still believe the effects of acupuncture are potentially profound, I just think it has less to do with me and the intricacies of Chinese medical thinking, and more to do with people actually getting acupuncture - and also how responsive to acupuncture a given individual is.
There is a doctor in England named Felix Mann who has a theory that there are people who respond to acupuncture, a group of people who respond extraordinarily well which he has dubbed 'super-responders', and a small set that don't respond. My experience has been this as well, so this makes sense to me. There are some people who you do the simplest thing to and they get these amazing results, and there are a few who you can try everything on and nothing happens of any significance.
Mostly, people feel better with acupuncture and basic function improves (they sleep better, they poop better, they have greatly mental clarity and are less stressed), and for most conditions acupuncture is helpful to some degree.
OK! So, other than touching on my direct experience that acupuncture tends to provoke some kind of general parasympathetic response that seems to be beneficial to most people, I haven't really touched on how it works have I? To be continued...