Why do we have kidneys?

Your kidneys are vital for your survival. They have several extremely important functions. Their main tasks are to filter waste substances out of your blood and balance the levels of salts and water in your body.

The location of your kidneys

Most people have two kidneys, although it is possible to live a normal life with only one. They are shaped like beans and roughly the same size as your fist. To find out where your kidneys are located, do this: put your hands around your hips, then slide them upwards until you can feel your ribs with your fingers. Your kidneys are then at the back, under your thumbs. You cannot feel them, but they are right there, well embedded in your body.

How your kidneys work

Depending on your weight, you have 4.5-6.5 litres of blood circulating in your body. The blood is transported into and through your kidneys via the renal arteries.
Every day approximately 1,500 litres of blood passes through your kidneys and are treated, thanks to roughly one million small filters. These filters are called nephrons and are so small that you need a microscope to see them. Most kidney diseases are caused by attacks on the nephrons. When they lose their filtering abilities, dangerous levels of fluid and waste products can build up.

Your blood needs to be cleaned

When your body has taken the nutrition it needs from the food you eat, some waste products are sent back to your blood. One of the key functions of your kidneys is to continuously filter these waste substances out of the blood. You could say that your kidneys are the ‘cleaning station’ for your blood. If the kidneys do not remove the waste products, they will build up in the blood and severely damage your body.

Your kidneys have other functions

Your kidneys have other functions, beyond cleaning your blood. They are important to balance the volume of fluids and minerals in your body.

Getting rid of wastes and water
The substances that are filtered in the kidneys are mixed with water and transformed into urine. The urine leaves the kidneys through small tubes (the ureters) and is collected in the bladder. The urine containing the waste products and water leaves your body through the urethra.

Kidneys are always busy
The kidneys also produce active vitamin D which is needed for absorbing calcium from food. Calcium is, among other things, important for building your bones. In addition, your kidneys help regulate your blood pressure and stimulate the production of red blood cells. There is no doubt that the functioning of your kidneys is vital to your well-being.