Swertia species, particularly Swertia chirayita, have been used in traditional medicine systems like Ayurveda and Traditional Chinese Medicine (TCM) for a variety of ailments, including edema. In these systems, Swertia is considered a bitter tonic and is believed to have diuretic properties, which could theoretically help reduce fluid accumulation in the body. Historical Ayurvedic texts mention Swertia as a component of formulations used for "Shotha" (the Sanskrit term for swelling or edema).

However, scientific validation for Swertia’s use in edema is limited. Some animal studies have suggested that extracts from Swertia species may possess mild diuretic effects and could help reduce inflammation, which might indirectly support traditional claims. For example, a few pre-clinical studies have demonstrated anti-inflammatory and diuretic activity in animal models, but these studies are preliminary and not specific to clinical cases of edema in humans. No well-designed human clinical trials have directly evaluated Swertia’s efficacy for treating edema.

In summary, the use of Swertia for edema is primarily supported by traditional medical practices rather than robust scientific evidence. The evidence rating is low (2/5), reflecting the reliance on historical use and limited preclinical findings, with a notable lack of high-quality clinical research. Anyone considering Swertia for edema should consult a healthcare professional and not rely solely on traditional remedies, especially for a potentially serious condition like edema.