Anatomical Indicators of Deerghayu (Longevity)

Ayu (lifespan) has remained an enduring focus of inquiry across classical Ayurvedic scholarship and contemporary biogerontology. Within classical Samhitas, particularly Charaka Samhita (Sharira Sthana and Vimana Sthana) and Sushruta Samhita (Sutrasthana), the estimation of lifespan is prioritized prior to therapeutic intervention. Classical authors classified longevity into Deerghayu (long lifespan), Madhyamayu (moderate lifespan), and Alpau (short lifespan). While contemporary medicine evaluates longevity through physiological parameters, biomarkers, and genetic architecture, ancient anatomical masters formulated a comprehensive somatic appraisal scheme based on structural morphology (Anga-Pratyanga Sharir), somatic symmetry (Pramana and Samhanana), deep tissue concealedness (Gudha Sandhi-Sira-Snayu), and tissue excellence (Dhatu Sara). This review presents a critical, doctoral-level anatomical synthesis of Deerghayu Lakshana (morphological indicators of longevity) extracted from classical literature and evaluates them through modern functional anatomy, developmental biology (Developmental Origins of Health and Disease - DOHaD), biomechanics, and anthropometric science. The integration of ancient observational morphology with contemporary structural science provides a robust baseline for morpho-phenotypic longevity appraisal and constitution-guided predictive medicine.