Meridians are pathways through which energy flows in traditional Chinese medicine (TCM) ). They are not real anatomical structures, and scientists have found no evidence that supports their existence). However, in TCM, meridians are considered as energetic highways in the human body that allow for the flow of energy, known as Qi, to circulate throughout the body. Meridians exist in corresponding pairs and each meridian has multiple acupuncture points along the pathway. There are fourteen main meridians throughout the body, with one running up the center of the body on the front, another running along the spine, and the other twelve running from head to toe along the rest of the body. Each limb is traversed by six channels, three that are considered yin in nature and three that are considered yang in nature. Yin channels are located on the inside surfaces and the yang channels are located on the outside surfaces. Each meridian is associated with certain types of vital energy or Qi, qualities (such as cooling or warming), sense organs, emotions, and elements.

It is important to note that meridians in TCM are different from meridians in geography. In geography, a meridian is an imaginary north-south line on the Earths surface that connects both geographic poles and is used to indicate longitude.