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 10/21/2018
Updated by: Jennifer K. Mannheim, ARNP, Medical Staff, Department of Psychiatry and Behavioral Health, Seattle Children's Hospital, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.