The kidneys filter wastes and excrete fluid when the pressure of blood in the bloodstream forces blood through the internal structures of the kidney.
Review Date 4/15/2019
Updated by: Walead Latif, MD, nephrologist and Clinical Associate Professor, Rutgers Medical School, Newark, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.