(American College of Physicians-American Society of Internal Medicine) -- Acupuncture, an ancient East Asian therapy that is becoming more widespread in the West, is the subject of the ninth article in a series on complementary and alternative medicine in Annals of Internal Medicine.

Acupuncture uses various procedures, such as heat and pressure but mainly fine needles, to stimulate points on the body to relieve pain. The Annals article reviews the historical and theoretical framework of acupuncture, the scientific evidence for its claims to effectiveness, its safety profile, and the training of practitioners in the United States.

Randomized trials have found that acupuncture is effective for treating vomiting after chemotherapy or surgery, and nausea associated with pregnancy. It may be effective for relieving dental pain. It is not effective in treating ringing in the ears or addiction to alcohol, tobacco or chemicals. Several clinical trials have come to contradictory conclusions on its effectiveness in treating chronic pain, back pain and headache.

Acupuncture appears relatively safe, if practiced by trained acupuncturists. It can produce complications associated with any type of needle use. The number of acupuncturists in the United States, estimated at about 11,000 practitioners without traditional medical degrees and 3,000 acupuncturists with medical degrees, is expected to double by 2005 and quadruple by 2015.