Acupuncture is an age-old healing practice of traditional Chinese medicine in which thin needles are placed at specific points in the body. It's primarily used to relieve pain but also has been used to treat other conditions. More than 3 million Americans use acupuncture, but it is even more popular in other countries.
Acupuncture seeks to release the flow of the body's vital energy or "chi" by stimulating points along 14 energy pathways. Some scientists believe that the needles cause the body to release endorphins -- natural painkillers -- and may boost blood flow and change brain activity. Skeptics say acupuncture works only because people believe it will, an effect called the placebo effect.