What is Glomerular filtration rate?
{{no sources||}} [[File:Gray1130.svg|thumb|right|200px|A single glomerulus]] [[File:Inner view of fenestrae in capillary of glomerulus in Scanning Electron Microscope, magnification 100,000x.GIF|thumb|right|200px|The inside of a glomerulus showing the filter]] '''Glomerular filtration rate''' ('''GFR''') is a [[Medical test|test]] used by [[physician]]s and other medical professionals to see if the [[kidney]]s are working correctly. In basic terms, it is a [[measurement]] of how much liquid and waste is passing from the [[blood]] through the tiny [[filter]]s in the kidney, called the [[glomeruli]], and out into the [[urine]] during each minute. The test measures how much [[creatinine]] is in the blood. This shows how well the kidneys are performing. In a normal healthy person the GFR stays close to the same value all of the time. The test is done by taking blood from a person and sending it to a [[laboratory]]. Normal values are between 90[[Millilitre|ml]]/[[Minute|min]] and 110[[Millilitre|ml]]/[[Minute|min]]. A value below 60ml/minute means the person has [[chronic renal disease]] and a value below 15ml/minute means the person's kidneys have stopped working. __TOC__ ==Reasons for doing the test== Measurement of the GFR can be very helpful to [[Medical professional|medical professionals]]. It helps them decide if a person has a disease of the kidneys or not. A normal value for GFR is between 90-110ml/min. This will normally go down in older people. It will also go down in people with [[Renal disease|kidney disease]]. As well as helping a medical professional [[Diagnosis|diagnose]] a kidney disease, the GFR is also used to monitor the progress of a disease. ==Method of testing== The test begins by taking blood from a person's [[vein]]s. The most common places are the vein at the [[Antecubital vein|elbow]] and in the veins on the back of the hands. People usually feel a sharp stinging pain when the [[Hypodermic needle|needle]] enters their skin. After the blood is drawn out, it is sent to a [[medical laboratory