Acupuncture at certain points removes the block and ensures smooth flow of energy

Sources vary on the number of meridians, with numbers ranging from 14 to 20.

One commonly cited source describes meridians as 14 main channels "connecting the body in a web like interconnecting matrix" of at least 2,000 acupuncture points.

Acupuncture can cause multiple biological response.

Local and peripheral

Opioid  peptides are released during  acupuncture  encephalin. serotonin endorphin

Stimulation may activate pituitary gland and hypothalamus resulting in systemic effects