Poria mushroom (Poria cocos), also known as Fu Ling in Traditional Chinese Medicine (TCM), has a long history of use for various urinary and renal disorders, including nephritis (inflammation of the kidneys). In TCM, Poria is valued for its diuretic and "dampness-draining" properties, which are believed to support healthy kidney function and reduce fluid retention—key concerns in nephritis. Classical herbal texts frequently mention Poria as an ingredient in formulas designed to treat symptoms associated with nephritis, such as edema, oliguria (reduced urine output), and discomfort in the lower abdomen.

Modern pharmacological studies have begun to investigate Poria's effects, revealing possible anti-inflammatory, immunomodulatory, and diuretic activities in vitro and in animal models. However, direct clinical evidence for its efficacy in human nephritis is limited, with only a few small-scale or low-quality studies available. As a result, most of the support for Poria's use in nephritis comes from its established role and documented usage in traditional medicine, rather than from robust scientific validation. Further research, including well-designed clinical trials, would be necessary to confirm and clarify its potential benefits for nephritis in humans.