The primary function of the kidneys is to remove excess water and waste products dissolved in the urine. The kidneys are responsible for maintaining the amount and proportion of substances dissolved in the water in our body. They adapt the production of urine depending on the amount of food and drink that has been taken and the number of exits that have been by other means such as feces and sweat. Urine production is made in the kidneys and after passing through the ureters it is stored in the bladder. When it is full, urine comes out through a hole called the urethra. Under normal conditions, the amount of urine produced daily is around one and a half liters, and we should be alerted if the amount is much less or greater or if the urine appears cloudy, reddish or too clear.
The kidneys receive large amounts of blood, which contains water with many dissolved substances, through their arteries. Blood constantly circulates through the two million tiny filters (called glomeruli) that the kidneys contain. It is in the glomeruli where that liquid is filtered that will give rise to the final urine that we eliminate. Depending on the needs of the kidneys, they more or less concentrate the urine.
The products that have to be eliminated are, above all, the non-useful remains of the proteins that food contains and that have been used for the continuous renewal of the body structure: muscles, blood, bones, etc. The most abundant wastes, included in the urine, and that are requested more often in blood tests are: urea, creatinine, uric acid, calcium, phosphorus and others.
Also other substances are eliminated dissolved in the water from the urine. For example, many drugs are eliminated by the kidneys. This is important as these drugs cannot be removed from the body properly when kidney function is severely reduced in severe disease. For this reason, you should discuss with your nephrologist all the medications you take or will take.
In addition to removing waste and fluids from your body, your kidneys perform other important functions:
They produce hormones that help your body to:
Chronic kidney disease is a condition that indicates that the kidneys are damaged. Damaged kidneys cannot maintain body health. They can't filter blood well enough, and they can't do their other jobs as well as they should.
Chronic kidney disease occurs slowly, and in stages. Most people in the early stages of the disease have no symptoms. They may not even know that something is wrong. But if it is found and treated, kidney disease can often be delayed or stopped.
If kidney disease worsens, waste may build up in high levels in the blood, causing general malaise. The patient may have other problems such as high blood pressure, a low red blood cell count (anemia), bone weakness, poor nutrition, and nerve damage, as well as an increased chance of heart and blood vessel disease.
If the disease continues to get worse, it can lead to kidney failure. This means that the kidneys no longer work well enough to keep the patient alive, and he needs treatment such as dialysis or a kidney transplant.
Dialysis is a procedure that removes waste products and excess fluid from the blood that the kidneys cannot remove. Dialysis performs the function that the kidneys normally do when they are healthy.
There are two types of dialysis: hemodialysis and peritoneal dialysis. The choice of one or another modality depends, in some cases, on strictly medical criteria. But in others, it is the patient who plays a decisive role in decision-making.
Dialysis is a life-long treatment, unless kidney function recovers, a rare situation, or a kidney transplant occurs.