Acupuncture is the stimulation of specific points and meridians on the body by insertion of thin, sterile, stainless steel needles to elicit a physiological response. A meridian is a pathway that is associated with and influences specific nerves, blood vessels, tendons, muscles, and organs. Acupuncture needles can relieve pain by stimulating the nervous system, promoting blood circulation, and relieving muscle tension. Acupuncture can treat internal disorders by balancing the autonomic nervous system to enhance organ function and regulate breathing, heart rate, and hormone production. Overall, these mechanisms promote healing and homeostasis in the body. The specific point selection directs these mechanisms to certain body parts or organ systems.