Background: Sleep, or Nidra in Ayurveda, is a foundational pillar of health alongside food (Ahara) and lifestyle control (Brahmacharya). The WHO recognises insufficient sleep as a global health epidemic, with India ranked as the second most sleep-deprived nation. Modern life often prioritises work, digital engagement, and social interactions over adequate sleep. Objective: This write-up explores the significance of Nidra through a synthesis of classical Ayurveda and contemporary sleep science, focusing on sleep hygiene practices. Methods: A narrative review was conducted using texts from the Brihattrayi (Charaka Samhita, Sushruta Samhita, Ashtanga Hridaya), peer-reviewed journals, WHO and NSF reports, and classical commentaries. Analyses of clinical implications were performed. Results: Nidra has crucial physiological roles, affecting memory, hormone secretion, immune function, cardiovascular health, and metabolism, all linked to Ayurvedic concepts like Dhatu Poshana and Ojas. Psychologically, sleep deprivation disrupts cognition, emotions, and mental health, significantly increasing depression risk. Socially, inadequate sleep affects academic performance, economy, public safety, and family dynamics, illustrating modern consequences of Prajnaparadha. The write-up proposes an integrative Nidra-Preserving Protocol combining Dinacharya/Ratricharya with evidence-based sleep hygiene. Conclusion: Both Ayurveda and modern sleep science emphasise Nidra's vital role in biological, psychological, and social health. Prioritising sleep as a key aspect of preventive medicine is a pressing health imperative for the twenty-first century.