Glomerular filtration (GF)
The main mechanism used by the kidneys to excrete excess water and waste products. In many types of kidney diseases GF is not functioning properly, excreting too little of some and/or too much of other substances. Downstream in the kidney, another mechanism, called tubular reabsorption, will concentrate urine, by reabsorbing excess water and other substances the body needs, but this mechanism may also be damaged. Both GF and tubular reabsorption depend strongly on adequate blood supply, and diseases affecting blood supply to the kidneys may thus also damage the kidneys. The measure of GF is glomerular filtration rate, GFR, and is expressed in ml/min.
GE Healthcare Glossary