Acupuncture (Chinese: 針灸, Pinyin: zhēn jiǔ) is a broad term covering techniques for inserting and manipulating thin needles into "acupuncture points" on the body in order to restore health and well-being. In the West, it is associated with Traditional Chinese medicine, or TCM along with herbal medicine and tui na. Other types of acupuncture, notably Japanese, Korean, and classical Chinese acupuncture, are practiced and taught throughout the world.

TCM is based on a different paradigm than scientific biomedicine. Acupuncture treats the human body as a whole. Many different aspects of a persons health and lifestyle are considered. Disease is understood as a loss of homeostasis in the many body systems. Treatment of a disease or illness is attempted by modifying the activity of one or more systems of function through the activity of needles, pressure, heat, etc. on specifically located points called "acupuncture points" in English, or "xue" (穴, cavities) in Chinese. This is referred to as treating "patterns of disharmony".

Treatment of acupuncture points may be performed along the twelve main or eight extra meridians, located throughout the body.

The movement of qi through each of the twelve channels is comprised of an internal and an external pathway.
Traditional Chinese medical theory holds that acupuncture works by normalizing the balance of qi "vital energy" throughout the body. Pain or illnesses are treated by attempting to remedy local or systemic accumulations or deficiencies of qi. Pain is considered to indicate blockage or stagnation of the flow of qi, and an axiom of the medical literature of acupuncture is "no pain, no blockage; no blockage, no pain". Many patients experience  sensations of stimulus known in Chinese as "deqi" (得氣 "obtaining the qi").

The acupuncturist will decide which points to treat by thoroughly questioning the patient, and utilizing the diagnostic skills of traditional Chinese medicine. 

There are also theories being developed to explain effects observed for acupuncture within the orthodox Western medical paradigm.