The acupuncture zero point is located on the external ear at the base of the cartilage ridge that forms the top front of the ear, right above the opening to the ear canal. Stimulation of the zero point is believed to affect the vagus nerve.
Stimulation of the zero point is believed to affect the entire body rather than a specific organ or limb. It is thought to act to balance the body, or to bring the body back into an idealized state. It is often used as part of sedation and pain treatment protocols. Identified as the umbilical cord of the inverted fetus, some think it represents the shape of the ear.