No one really knows exactly how acupuncture works - but then no one knows exactly how anesthesia works either, or aspirin. The front-runner theories right now have to do with "slow" and "fast" pain signals and the ways they travel to the brain.
But several thousands of years of documented acupuncture practice does allow us to predict the outcome of hair-thin needles inserted into very specific points in the body. Everyone is different, so there are varying degrees of success with each treatment, but it's pretty predictable.
Every acupuncturist works differently, just like no two cooks make the same spaghetti sauce. The outcome will generally be the same, but the points used may be completely different. We like to use the "long lever" treatment. Here's what I mean: If you want to move a big boulder (remember this from third grade science?), you don't just push the boulder. What you do is find a long piece of wood to maneuver under a section of the boulder and push down on the lever to lift the boulder out of its spot.
It just so happens that there are very strong acupuncture points on the forearms and lower legs that work just this way. Their power is concentrated along concentrated lines of energy called meridians (or channels or vessels), and their lever action is aimed at particular body systems like the digestive system, the reproductive system or the respiratory system (to name a few). Depending on the location of the point on that line of energy, it will treat a different condition relating to the system (like heartburn or nausea or indigestion).
There are also very strong points on the ear which serve to balance all the functions of the body, and we will use these points in nearly every treatment.
And lastly, there are very powerful points on the scalp which correspond to the brain function underlying those points. Don't worry, for these points the needle is inserted just under the scalp - we won't be trying to stick it through the bone! Treatments using scalp acupuncture are used for patients with brain trauma, stroke, or paralysis, and they are hugely successful.
Now, you probably think you're scared of needles, but if so you may be thinking of hypodermic needles like the ones used for vaccinations. Acupuncture needles are just about as big as a pine needle, and they are not hollow. Nothing is injected with them and nothing is left under the skin. They are stainless steel and we use each sterile needle only once, then dispose of it just like hospitals do.
The big question is, "does it hurt?" Sometimes you'll feel a pinch like a mosquito bite (less than a red ant sting), but often there will be no sensation when the needle is inserted (and besides, we practiced really hard to have good technique). As you are resting, you may begin to have a sensation around the needle, or along the meridian the needle is associated with. Different people will experience it as heavy, or zingy; or they will associate it with a reduction in pain or discomfort.
Some people report a good result while they are resting with the needles in. Others may feel better immediately after the treatment. Still others have a delayed reaction, and some only have a cumulative result after a number of treatments. There's no way to know ahead of time which type you will be, which is why we recommend that you give it a few treatments to see how you will react.