Acupuncture:

Eastern Model:
In Traditional Chinese Medicine (TCM) style acupuncture, diagnosis and treatment is based on the Chinese concept of qi (energy) flowing through specific pathways in the body. Any imbalance or disruption in this flow can result in illness. An important point to this concept is that body and mind are intimately connected. Through a thorough intake, exam, pulse and tongue diagnosis, the acupuncturist can determine the nature of the disharmony. Very small disposable sterile needles are then inserted at precise locations to help the body restore its natural state of health.

A Western view:
TCM uses many terms that those of us who grew up in a western society may not relate to or understand. Here are a few examples of how the effects of acupuncture can be explained in western terms:
Specific points on certain pathways have shown very specific effects on bodily functions. When points on what is known as the heart meridian are needled there is a calming effect on our nervous system. When certain stomach points are needled digestive fluids and peristalsis are affected. Some points have a stimulating effect on our hormones. And other points stimulate uterine contractions. A point named guang ming (bright light) has been shown through brain imaging to stimulate the same brain area as the optic nerve. And some points have an immune boosting effect raising our white blood cell count.
These examples help give us an idea of why acupuncture can help restore health simply by the insertion of needles.