Although more meridians exist, most treatments are administered on 12 major ones. According to acupuncture theory, pain and illness result from obstructions to the flow of Qi. The goal of treatment, therefore, is to restore the flow of Qi by stimulating the acupuncture points. Needles are placed at selected acupuncture points at different depths of insertion for various lengths of time. Sometimes heat is applied to the acupuncture points in a procedure called moxibustion.
Pain relief is the most common reason people seek acupuncture.
Considerable research has been done that demonstrates that acupuncture does produce analgesic effects due to release of opioid peptides, alteration in the secretion of neurotransmitter and neurohormones, changes in blood flow, and activation of the hypothalamus and pituitary gland. Although the mechanism of action is unknown, there is evidence indicating that immune function is stimulated with acupuncture. Despite the fact that research is inconclusive regarding benefits of acupuncture for treating other conditions, many people have claimed this modality has helped them with asthma, addictions, fatigue, depression, and other conditions. Complications from acupuncture are rare. There is a risk of infection if needles are reused, however, it is highly unusual to find an acupuncturist who doesn't use disposable needles.