Physiological fingerprint of urine formation based on Prakriti (Body Constitution)

Background: Ayurveda, a traditional Indian medicine system, emphasises Prakriti (body constitution) for personalised healthcare. This concept suggests that an individual's innate constitution, determined by the predominance of three Dosha (Vata, Pitta, and Kapha body humor) at conception, influences their physiology. Understanding this physiological basis of urine formation in the context of Prakriti is crucial for a personalised approach to health and therapeutics. Objective: The present review aims to analyse the influence of individual body constitution (Prakriti) on urine production, focusing on key physiological factors as described in Ayurveda classics and supported by contemporary scientific understanding. It seeks to explore the differences in urine formation across various Prakriti types. Observations: Ayurveda describes urine formation originating from the Pakwashaya (large intestine) through Sara-Kitta Vibhajana (division of nutrients and waste), with final collection in the Basti (urinary bladder). Structures like Purishadhara Kala (mucous membrane of the large intestine and rectum), Mutravaha Nadi (Urinary Ducts or Urinary Channels), and Gavini (~ureter) facilitate this process, aligning with modern understanding of kidneys, ureters, and bladder function. A key observation is that Pitta Prakriti individuals exhibit a higher frequency and quantity of urine compared to other types. This is attributed to their elevated metabolic rate, as Pitta signifies the heat factor regulating metabolism. The normal urine quantity of 768ml mentioned in Ayurveda classics is comparable to the contemporary range of 800-2000ml per day. Genetic variations influencing metabolism and thirst mechanisms, such as the Median Pre-optic Nucleus (MnPO) of the Hypothalamus, are suggested as potential reasons for these individual differences within physiological limits. Conclusion: The review concludes that there is a significant physiological variation in urine formation among individuals, primarily influenced by their genetically determined Prakriti, especially the dominance of Pitta Dosha. Individuals with Pitta Prakriti demonstrate a higher metabolic rate, leading to increased production of excretory products, including urine. The findings reiterate the importance of considering Prakriti for personalised diagnostic and therapeutic approaches.