Thinner needles may be flexible and require tubes for insertion.
The skin is sterilized and needles are inserted, frequently with a plastic guide tube.
Needles may be manipulated in various ways, including spinning, flicking, or moving up and down relative to the skin.
Since most pain is felt in the superficial layers of the skin, a quick insertion of the needle is recommended.
An overview of Cochrane reviews found that acupuncture is not effective for a wide range of conditions, and they suggest it may be effective for only chemotherapy-induced nausea/vomiting, postoperative nausea/vomiting, and idiopathic headache.
In the 20th century, as it spread to the United States and Western countries, the spiritual elements of acupuncture that conflict with Western beliefs were abandoned in favor of tapping needles into nerves.