1. Mind–Body Medicine, 2. Biologically based practices, 3. Energy Medicine, 4. Manipulative and Body-based practices, and 5. Whole Medical Systems.
Subtle energy, which seems to sustain and promote life processes in the biological system. Subtle energy is another term used along with Energy Medicine. Here the energies activating a person are subtle or of very low intensity. Low levels of energy are measurable through a human biofield. There are four basic types of energies enumerated in Physics; they are strong and weak forces at the nuclear level, gravitational, and electromagnetic forces. Of these, electromagnetic (or, its equivalent, acoustic) is the only one that is easily manipulated at the present time.
Acoustic energy could be transformed into electromagnetic or vice versa through a material property known as piezoelectricity. Many tissues of the body are known to be piezoelectric; hence, any electromagnetic input to the body is transformed into acoustic and any acoustic input could be transformed into electromagnetic energy. Thus, the body is bathed in both electromagnetic and acoustic energies of various frequencies and intensities.
Some examples of subtle energies that exist are things like prayer or non-contact therapeutic touch. In these examples, there is no measurable physical energy that seems to be taking part in the interactions. Although the effects of prayer and therapeutic touch are well-investigated and reported, the energy type and hence the mechanism of action can only be surmised. The energy of chi (or, qi) or prana is not measurable; however, the interaction of chi or prana with the biological system may be measured in the human biofield. For example, with the appropriate flow of prana, the tissues are healthy; thus, chi gong or yoga may be thought of as stabilizing the flow of prana in the body.