Nidāna-sthāna, the second chapter of the ancient Ayurvedic compendium Sushruta Saṃhitā, is a classical treatise on causes and clinical recognition of disease. Traditionally attributed to Sushruta and refined over centuries in classical India, this section systematically maps nidāna (etiology), samprāpti (pathogenesis) and lakṣaṇa (symptoms) across many disorders. Its key themes include doshic imbalance, environmental and lifestyle causes, stages of disease, prognosis and preventive insight. Rich in clinical observation and diagnostic method, Nidāna-sthāna forged Ayurveda’s approach to rational diagnosis and epidemiology. Today its emphasis on causation, individualized assessment, preventive care and detailed symptomatology resonates with integrative medicine, public-health thinking and chronic-disease management.