In yoga, relaxation is clearly defined as a state in which there is freedom from physical, emotional and mental tension. Practices such as yoga nidra are designed to systematically soothe away tensions at all these three levels.
Yoga nidra induces deep relaxation of the whole physical body. The muscles, nerves, heart, respiratory system, circulatory system, the ligaments, the brain, the eyes, the abdomen, the forehead, the kidneys . . . the whole body is systematically relaxed.
Next, yoga nidra gradually releases emotional tensions that are embedded in the mind. This does not happen overnight, but takes time and regular practice of yoga nidra combined with other forms of yoga. It releases fears, anger, jealousy and other emotions that cause tension. All the emotions are brought to the surface, to conscious perception, and then discarded. They seem to evaporate, cease to cause inner turmoil and cease to have negative influences in one’s life. The more that they are removed, the more one relaxes, not only during yoga nidra practice, but in everyday life.
Yoga nidra tackles mental tension, which can be regarded as those aspects of the mind that are based on ignorance and wrong thinking. We are conditioned by the circumstances of life. These produce tension. Yoga nidra slowly helps to whittle away false thinking and ignorance. We gain deeper insight into our own being and the nature of existence. We start to plummet into the depths, or rise to the heights of the mind. The tensions of ignorance are gradually removed. This leads to greater and greater degrees of permanent relaxation.
Real relaxation comes only when you achieve a state of what can be called spiritual awareness. One sees a background and order behind all things, and begins to flow with the stream of life. One ceases to worry. This is real relaxation. It comes through the practice of yoga in general, aided by yoga nidra.