The kidneys are invariably called the workhorses of the body. Each day they process about 180 litres of water – that is the amount a bath holds up to the overflow level – and 1.5kg of salt.15 They are startlingly small for the amount of work they do, weighing just 5 ounces (140g) each. They are not in the small of the back, as everyone thinks, but higher up, about at the bottom of the ribcage. The right kidney is always lower because it is pressed down upon by the asymmetrical liver.
