Vyadhikshamatva — The Science of Immunity
Vyadhikshamatva ('the capacity to resist disease') is Ayurveda's concept of immunity — a dynamic quality that varies with constitution, season, lifestyle, and the integrity of Ojas, and that can be systematically cultivated.
Vyadhikshamatva (Vyadhi = disease, Kshamatva = capacity to resist or tolerate) is Ayurveda's concept of immunity and disease resistance. It encompasses two aspects: Vyadhibalavirodhitvam (capacity to resist the onset of disease) and Vyadhinutpanapratibandhakavam (capacity to reduce the severity of established disease). Factors that strengthen Vyadhikshamatva include: strong Agni (digestive fire), healthy Ojas, proper Dhatu formation, balanced doshas, proper sleep, appropriate diet, Rasayana therapy, and positive psychological states. Modern immunology has precisely validated this multi-factor model: innate and adaptive immunity are regulated by sleep quality, nutritional status, stress hormones, gut microbiome integrity, and psychological state — exactly the factors Ayurveda identified as determinants of Vyadhikshamatva.
The person with strong Vyadhikshamatva remains healthy even when exposed to disease; the person with weak Vyadhikshamatva falls ill even from minor causes.
Psychoneuroimmunology has confirmed that stress, sleep deprivation, and poor nutrition impair NK cell activity, reduce antibody response, and increase susceptibility to infection — precisely the immune-weakening conditions Ayurveda associated with Ojas depletion and loss of Vyadhikshamatva.
Charaka Samhita