In our clinic, and in clinics around the world, patients often ask "How Does Acupuncture Work?".  The truth is we simply do not know, but most are very, very glad it does....  Saying we don't know exactly, however, is very different from saying we have no ideas or no signposts along the way to understanding all of the mechanisms.  There are often very reliable and observable changes to the stimulation of various acupuncture points.  The problem from a research perspective is there are often many physiological, chemical, hormonal, vascular, etc... changes from even one acupuncture point and obviously more so during a treatment with multiple points - all of this making research very difficult.

There are from time to time some studies done that give us insight into the internal changes of acupuncture.  In this study, researchers from the Tohuku University Graduate School of Medicine evaluated vascular changes in the brachial artery from acupuncture point stimulation.  Researchers used measurements of blood flow volume (BFV) as it is a good indicator of internal circulation in the tissues and organs generally.

Researchers recruited 75 healthy volunteers and divided them evenly into (1) a ST 36 acupuncture point group, (2) a LV 3 acupuncture point group, (3) a "non-acupoint" group which used a point very near an extrapoint for shoulder pain (which brings up a complex issue with using sham points - saved for future articles...).

Researchers found that needling LV 3 significantly increased blood flow volume in the brachial artery and needling ST 36 decreased blood flow volume in the brachial artery.  The "non" point also created hemodynamic changes.  For acupuncturists this -could- be read as LV 3 created more movement (i.e. it's use in resolving stagnant liver qi), and ST 36 created a more consolidating affect (i.e. it's use in tonifying the body and strengthening immunity overall).  Further studies with more complex analysis would have to be done to verify concepts like this.  All things considered studies like these give us some valuable insights into how acupuncture works.