Punarnava (Boerhavia diffusa) has a long history of use in Ayurvedic and other traditional systems of medicine, particularly in India, for supporting urinary and bladder health. In Ayurveda, punarnava is classified as a diuretic (mutrala) and is traditionally used to support normal urine flow, reduce water retention, and maintain proper functioning of the urinary tract. Its name literally means "renewer," referencing its reputed rejuvenating effects on the body, including the bladder and kidneys.

Several classical Ayurvedic texts describe punarnava as helpful in managing conditions such as urinary tract disorders, edema, and inflammation of the urinary system. The root is most commonly used and is often included in polyherbal formulations for urinary health.

From a scientific perspective, there are some preclinical studies (mostly in animals or in vitro) suggesting diuretic, anti-inflammatory, and nephroprotective effects of punarnava extracts, which may support its traditional use for bladder and kidney health. However, robust clinical trials in humans are limited, and the evidence is not strong enough to fully validate these uses through modern scientific standards. Thus, the rating reflects strong traditional use with limited but suggestive scientific support.