Though we have recommended yoga nidra as a method of inducing sleep, you should remember that there is a vast difference between the state of sleep and the state of yoga nidra. In Sanskrit sleep is called nidra. In nidra there is loss of awareness in both the inner and outer world. In yoga nidra there is loss of awareness of the outer world, but awareness of the inner world is retained. This is a profound difference. Nidra is unconscious sleep and yoga nidra is conscious sleep.
There is also a great difference in the results. Yoga nidra gives maximum relaxation to the mind and body in the minimum time. It is said that one hour of yoga nidra is equal to four hours of normal sleep. After a successful yoga nidra practice there is often a feeling that ‘sleep’ has not occurred. A lady from Madras claimed that she had not slept for twenty-nine years, not even for one minute. Actually, she did sleep, but it was in the form of conscious sleep. She was sleeping without necessarily closing her eyes and perhaps while performing other physical duties. Her sleep was of the type that one experiences in yoga nidra.