European White Birch (Betula pendula) has a long history of use in traditional European herbal medicine, particularly as a diuretic to support urinary tract and bladder health. In folk medicine, birch leaves and sometimes sap have been used to promote increased urine flow, which was believed to help "flush out" the bladder and prevent accumulation of waste products or urinary gravel. Several authoritative herbal texts, such as the German Commission E Monographs, acknowledge birch leaf for its traditional use in treating urinary tract conditions and as supportive therapy for bladder health.

Scientifically, the primary support for its use comes from its mild diuretic action, likely due to flavonoids and other phenolic compounds present in the leaves. However, robust clinical trials validating its effectiveness for bladder health are lacking. The evidence base is mainly historical and based on empirical use rather than controlled research studies. There are some in vitro and animal studies demonstrating anti-inflammatory and diuretic properties, but direct relevance to human bladder health remains unclear. As such, its use is best described as being justified by tradition, with limited scientific validation.