Ageing and Lifespan in ancient Indian medicine

The subject of ageing and lifespan was studied in ancient Indian medical texts, such as Carakasaṃhitā (CS), Suśrutasaṃhitā (SS), Aṣṭāṅgasaṃgraha (AS) and Aṣṭāṅgahṛdayasaṃhitā (AHS). According to the 4 texts, age was defined as the state of body dependent on the length of time lived, and was broadly divided into three periods—childhood (–16 years), adulthood (16–60 or 70 years) and senescence (60 or 70 years and over). Further SS and AS subdivided the age into smaller stages as follows: childhood —kṣīrapa, kṣīrānnāda, and annāda; adulthood — vṛddhi, yauvana, sampūrṇatā, and parihāni. While taking up the management of the patient, the physician should examine the lifespan as a starting point in diagnosis. To determine the lifespan of the patient, his body was first measured as a whole and then each of the body parts were measured in terms of aṅgula (finger\u27s breadth measurement) of his hand, and also his sāras were considered, depending upon the state (excellence, purity, and predominance) of each one of the dhātu and manas. The lifespan of the person depends on the interaction between the forces of daiva (deeds done in the previous life) and puruṣakāra (deeds done in the present life). There is considerable variation in the strength of both forces, with them possibly being mild, medium or intense. When both daiva and puruṣakāra are strong, the lifespan is long, happy and predetermined. while both are weak, the lifespan is short, unhappy and changeable. So the average human lifespan is clearly determined by both genetics and the environment in this view. A weak daiva can be subdued by a stronger puruṣakāra. Therefore a wholesome lifestyle is the basis of longevity and an unwholesome lifestyle will result in a short lifespan.We must understand that if we want to live longer, it is necessary to live properly