Understanding Kidney Function and Kidney Failure

In order to understand kidney failure, it is a good idea to understand how the kidneys are supposed to work and what they do for our body.  Our kidneys come as a paired set of organs located on the sides of the middle back. They play a crucial role in the body and act as a filtration system, ridding the body of toxins and byproducts of metabolism. They do this by filtering the blood and eliminating wastes through the urine. The kidneys also help regulate our blood pressure, control the production of red blood cells and regulate the body’s levels of calcium and body minerals.

In the absence of kidney failure, the normal kidney contains tiny microscopic units that are called nephrons.  The nephrons remove waste products and excess water from the food and liquid we consume.  It returns back to the bloodstream those things we need, like sodium, phosphorus and potassium, while it lets waste products pass through to the pelvis of the kidney, down the ureters and into the bladder.  When the bladder empties, the urine passes out of the urethra to the outside.

A kidney not affected by kidney failure generally makes erythropoietin, a hormone which turns on production of red blood cells.  In kidney failure, there is often anemia because of a lack of erythropoietin.  The kidney, when it perceives a lack of blood flow, creates a substance known a renin, which indirectly increases blood pressure.  The kidneys also help produce the active form of vitamin D, which controls the balance of calcium inside the body.

As kidney failure begins to develop, the kidneys do not function in the way they are supposed to function.  Many of the problems are genetic and aren’t due to anything a person did or didn’t do except in cases of diabetes, where poor diabetic control can contribute to damage to the kidneys prematurely. 

Early kidney failure in children can be diagnosed on intrauterine ultrasound before the baby is born or with testing of the urine and kidneys after the baby is born.  Kidney infections, slow growth in children and high blood pressure are signs of early kidney disease and possible kidney failure.

Kidney failure is the result of a loss of activity of the nephrons of the kidneys.  The kidney failure can be of a slower onset, when it is caused chronic kidney failure.  Alternatively, there can be a sudden insult to the kidneys, leading to acute kidney failure. In some cases, acute kidney failure can reverse itself if the insult is removed and the kidneys are allowed to heal. The only real treatment for kidney failure is dialysis, in which machines are used to filter the blood of the wastes in place of the kidneys.  Dialysis is generally done about three or more times per week to clear out the excess fluids and wastes from the blood stream.

The ultimate treatment for kidney failure is to undergo a kidney transplant.  A suitable donor must be found and then the new kidney is placed in the lower abdomen, just above the groin.