Yoga nidra

Yoga nidra () or yogic sleep in contemporary usage, refers to a state of consciousness that occurs between waking and sleeping and is usually brought on by guided meditation. 

The Upanishads and the Mahabharata, discuss a state known as yoga nidra, while Yoganidrā, a goddess, is mentioned in the Devīmāhātmya. In both Shaiva and Buddhist tantras, yoga nidra is associated with meditation, while the deep meditative state of samadhi is referred to as "yoganidra" in certain mediaeval hatha yoga writings. There is however, no precedent for the contemporary method of guided meditation in these books.  According to practitioners like Annie Payson Call and Edmund Jacobson, that originates from Western "proprioceptive relaxation" in the 19th and 20th centuries.

Dennis Boyes invented the approach in its current version in 1973,Boyes, Dennis (1973). Le Yoga du sommeil éveillé; méthode de relaxation, yoga nidra. Paris: Épi. OCLC 2283047. made popular by Satyananda Saraswati in 1976, followed by Swami Rama, Richard Miller, and others. It has since expanded globally. The U.S. Army uses it to help soldiers recover from post-traumatic stress disorder. PTSD hyperarousal symptoms, general sleep quality, and daily sleep-related dysfunction were significantly improved in veterans with the help of yoga nidra. Yoga nidra can help relieve stress.

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