Urine flow rate curve shapes and their descriptors

To review the descriptors and definitions of urine flow rate curve shape with a view to promoting greater clarity and to propose standard terms METHODS: A search was made in the PubMed and ICS standardization documents on urine flow rate curve shape.

The flow shape descriptors and their definitions are summarized and presented. "Normal" was widely used for describing a bell-shaped flow curve, and "plateau" was mostly used where the ICS describe "constrictive" flow shape. The use of shape descriptors "fluctuating," "compressive," "tower-shaped," and "intermittent" varied in the literature.

This survey provides an overview of flow shape descriptors and their definitions. We suggest it is clearer to use only descriptors that describe shape alone, that is, normal, fluctuating, intermittent, and plateau, with comments on symmetry and Q_max .