Reiki works in mystical and scientific ways

During the Reiki treatment the brain wave patterns of both giver and receiver become synchronized in the 7-8 Hz alpha state characteristic of deep relaxation and meditation; they pulse in unison with the Earth's magnetic field, the infinite energy source also known as the Schumann resonance. The pulsating biomagnetic field emitted from the hands focuses mainly in this alpha state and sweeps regularly from 0.3-30 Hz.

This range of frequency stimulates healing in the body, with specific frequencies being suitable for different tissues. Brain waves travel throughout the body and gather cumulative strength as they flow to the periphery, especially to the hands. During these moments the biomagnetic field of the practitioners' hands is at least a thousand times greater than normal. The effects are mirrored by the giver and receiver and both benefit from the treatment.

There are many other effects including emotional and hormonal ones that are much more difficult to measure scientifically. But all this supports the subjective experience of "oneness" and expanded consciousness elated by those who regularly practice Reiki.