The Three Fundamental Kidney Functions

The kidneys are remarkable, and without them working properly, we cease to exist. As important as they are though, many people do not stop and consider just what they do, and they don’t really have much more than a cursory knowledge of why they are important. It’s time to get a better understanding of the three fundamental kidney functions without getting overly technical. 

Filtration is perhaps the best known function. The kidneys filter the blood through their nephrons and they remove all of the waste from the blood. They take that waste, the ultra-filtrate, and then pass that through the kidneys into a series of collecting ducts. It is at these ducts that urine forms, passes into the bladder, and is eventually expelled as a waste product. Without the filtration aspect of the kidneys working properly, it would mean that the waste stays in the body. This becomes toxic to us.

The second fundamental function of the kidneys is re-absorption. This takes the water removed from the blood during the filtration process and transports that clean water back into the blood. 

The third function is secretion. Tubular secretion happens when material goes to the renal tubular lumen from the peritubular capillaries. This stage removes certain substances in the body that are simply too high, as well as natural poisons. For example, tubular secretion is the manner in which many drugs are eliminated from the body. Abuse of certain types of drugs, even some that people would not consider harmful in normal doses, can therefore be very damaging to the kidneys, which have to work hard to filter them from the body.

These are the three fundamental and basic functions of the kidneys. They are extraordinarily complex organs, and it is very important that you take care of them to maintain your health. 


Our informational articles are for your information only and are not intended as medical advice. Because everyone is different, we recommend you work with your medical professional to determine what’s best for you.