The life has been considered as a bioelectrical phenomenon, that is, our life relies on the bioelectricity that exists in our body. It is only because of the existence of this energy in our body that we can move, breathe, digest food or think. We call this bio-energy 'Prana' or 'Chetana'. The Chinese call it 'Chi'. This bio-energy is composed of two kinds of forces: 'Yin' and 'Yang'.

Yin is a negative force while Yang is a positive one. A person remains in good health if there is co-ordination, harmony and balance between these two forces. If the balance is disturbed or 'warped', that is, if the flow of one force in the-body is greater than the other, illness arises. These forces (bio-energy) flow through definite courses or channels in the body. These courses are called 'meridians'. The Chinese call them 'ling'. It is believed that there are in all 14 meridians in our body for the flow of bioelectricity or bio-energy (Chetana), Out of these 14 meridians, 12 meridians are present in pairs, each on the right side and the left side of the body, while the remaining two are single. One is on the vertical midline in front of the body and the other on the vertically central line on the backside of the body.

The 12 paired meridians comprise of 6 'Yin' meridians and 6 'Yang' meridians. 'Yin' meridians start from the toes or from the middle part of the body and go to the head or to the fingers of the hands. The 'Yang' meridians start from the head, the face or the fingers and go downside or to the middle part of the body (see figures 3.1 and 3.2).

These meridians which maintain the flow of bioelectricity have connection with the main organs (or systems) of the body. Each meridian has been given the name of the organ with which it is connected. One end of each meridian lies in the hand, the leg or the face and the other in one main organ. That is the reason why pressure applied to a particular point on the hand or the leg,' affects the remote organ connected with this point.