Question: What particularly interests you about the kidneys and blood etc? Also, do you think that there is anything else the kidneys might possibly assist with in the body other than what we already know?

Heather Eyre answered on 19 Jun 2013:

The kidneys do an amazing job at filtering out toxins in the blood, but that isn’t all they do!

They are quite a small organ, but they filter over 100mls of blood every minute, that means they filter your entire blood volume in less than 1 hour!

Whilst filtering the blood they also control blood volume (and blood pressure). As the blood is filtered some of the fluid becomes urine (along with all the toxic stuff like urea) and some of it goes back in to the blood (along with sugars and other useful stuff like potassium and sodium ions).

The kidneys can alter how much fluid goes back in to the blood meaning they keep blood volume roughly the same! If your kidneys didn’t let any fluid out you might end up like a giant water balloon! (don’t worry that won’t really happen!).

They also make some substances the body needs, like enzymes and hormones.

The kidneys are also important in dealing with any medicines you need to take, otherwise once you had taken something you’d never get rid of it.

We already know that the kidneys are busy little organs, but it wouldn’t really surprise me if they did do something else too!