The organs that filter waste are called


The kidneys clean a small glass of water full of blood every minute. This is made possible by a sophisticated system of tubes inside these organs. If that fails, however, it becomes life-threatening.

A complex structure

About twelve centimeters long, four centimeters thick and 150 grams - this is the profile of the vital organ. The kidneys are to the left and right of the spine, about the same level as the lower ribs. They are each protected by a layer of fat, which in turn is surrounded by tight tissue.

Directly below is the kidney cortex, which can consist of up to a million nephrons. These nephrons are nothing more than tiny subunits. With their complicated pipe system, they are the actual sewage treatment plants and transport and process the filtered urine.

The blood is carried from the heart to the kidneys via the main artery. After it has been cleansed there, it returns to the heart via a special vein.

The kidneys are supplied with much more blood than the liver or the heart muscle, for example. Although they only make up around one percent of body weight, one fifth of all blood flows through the kidneys.

A healthy kidney cleans around 95 milliliters of blood per minute. Because the blood is filtered about 300 times a day, 1500 liters flow through the kilometer-long tube system every day.

The kidney separates the reusable substances from those that have to be excreted. Decomposition products that arise during the metabolism are described by experts as requiring urine because they have to be excreted with the urine. These include urea, uric acid, and creatinine.

The kidneys also filter pollutants and drug residues from the blood and feed water, salts and nutrients back into the bloodstream.

The kidneys are not only responsible for recycling for a long time: The kidneys are also responsible for monitoring the oxygen content in the blood. If the oxygen level drops, they release the hormone erythropoietin.

As a result, more red blood cells are formed, which increase the oxygen content again. In addition, the kidneys constantly balance the body's salt and fluid balance. Blood pressure is also regulated by the kidneys.

When the kidney is sick

There are numerous disorders and diseases of the kidneys. This is particularly common Pelvic inflammation. This infection can be acute, but also chronic. The germs - usually bacteria - usually come from an infection of the urinary tract.

Kidney inflammation is particularly common in women. Pregnant women, menopausal women and older women are particularly affected. Kidney stones also promote this disease. Kidney inflammation is usually treated with antibiotics.

Kidney stones however, it is more of a male disease: men are affected twice as often as women. Tiny deposits form in the kidneys, which mostly consist of mineral salts (often calcium) and which the urine can no longer dissolve.

Those who drink too little, have a urinary tract infection and eat too much fat and protein are at a particularly high risk. Kidney stones can cause excruciating pain. If they don't go away by themselves, a doctor has to help. There are different methods for this, for example laser or ultrasound treatments.

At the chronicKidney failure the kidney tissue continues to recede. If one of the two kidneys then ceases to function, things can get tricky: the second kidney often takes over the tasks of the failed kidney and the disease can remain undetected for a long time. In addition, a damaged kidney can cause high blood pressure, which in turn can destroy the kidney that is still healthy.

The reasons for the disease are diverse, such as chronic inflammation, vascular calcification, diabetes or harmful drugs. In contrast to acute kidney failure, chronic kidney failure often progresses slowly. Indications are accumulations of fluid in the tissue, for example on the ankles, lower legs or on the face. Other symptoms may include painful urination and foamy urine.

You can stop kidney failure by treating the triggers. First, the blood pressure must be checked and, if necessary, adjusted. Avoiding protein and salt-rich food can also help.

If none of these therapies help, there is a risk of complete kidney failure. This can lead to life-threatening urine poisoning in the end stage. Hazardous waste and toxins then remain in the organism and are not excreted in the urine. Those affected often die of infections because the body is particularly susceptible to pathogens at this stage.

Waiting for the donor kidney

There are various therapies to prevent this. On the one hand, there is dialysis. A device to which the patient is connected takes over the tasks of the organ and removes, among other things, excess water and dangerous breakdown products from the body.