A Study of the Therapeutic Benefits and Physiological Effects of Yoga Nidra

Abstract

In the modern lifestyle, human health is being adversely affectedboth physically and mentallyby constantly rising mental stress, a sedentary routine, and work-related pressure. Against this backdrop, 'Yoga Nidra' from the Indian yogic tradition has emerged as a highly effective psychosomatic technique, regarded by Swami Satyananda Saraswati as being equivalent to Pratyahara. This practice offers a unique balance of physical relaxation and inner awareness. The primary objective of the present research study is to evaluate the therapeutic and health benefits of Yoga Nidra based on scientific evidence, and to provide a systematic analysis of its physiological and neurophysiological effects as well as the underlying mechanisms. This study adopts a descriptive literature review design as its secondary research methodology. Relevant peer-reviewed randomized controlled trials (RCTs), clinical trials, and neurophysiological studies were selected from the PubMed database based on systematic inclusion and exclusion criteria. An analytical analysis has been conductedbased on the thematic classification of qualitative and quantitative evidence from selected studiesregarding the therapeutic benefits and the effects on the autonomic nervous system, brain waves, endocrine markers, and sleep architecture. The results of the review indicate that Yoga Nidra is highly effective in reducing anxiety, depression, insomnia, post-COVID disorders, and chronic pain, as well as in enhancing overall mental well-being. At a physiological level, it calms sympathetic activity while enhancing parasympathetic nervous system function and vagal tone, leading to an immediate reduction in blood pressure and a positive improvement in heart rate variability (HRV). Additionally, it lowers the stress hormone cortisol and balances reproductive and metabolic hormones. At the neurophysiological level, Yoga Nidra increases endogenous dopamine secretion in the ventral striatum by approximately 65%, induces a state of 'local sleep' in the brain via slow delta waves, and curbs mind-wandering by loosening the connectivity of the Default Mode Network (DMN), thereby enhancing sleep efficiency and cognitive processing speed. Yoga Nidra provides deep relaxation to the brain even in the waking state, thereby reorganizing the nervous system, endocrine balance, and cardiovascular health. In the future, through large sample sizes and long-term trials, it could be established as a mainstream complementary therapy for various clinical disorders.