5 Facts About Kidneys

5 Facts about Kidneys

1. 1 in 1000 people are born with one kidney and come to no harm.

Most people have two kidneys – they lie under the ribs and above the waist (at the back), one on either side of the body. If you have one (born with one, or other if you have one removed), the  kidney grows (hypertrophies), and sustains the body.

They are higher up than most people think. The kidneys are protected from injury by a large layer of fat, along with your lower ribs and back muscles.

This diagram shows the location of the kidneys. The right kidney is slightly lower (and smaller), pushed down by the liver.

2. Kidneys filter (and clean) your blood 35x a day – with a blood volume of 5 litres. In this way, they are the body’s dustmen.

Even though 180L are filtered, 99% of the filtered liquid is put back (reabsorbed) into the blood as only 2L of urine emerge each day. This is how waste products and extra water are removed from the body. Crazy eh?!

Note. The ‘dustman role’ is just one of 7 functions of the kidney.

3. Small but important. Even though the kidney only accounts for 0.5% of the body’s weight on average (it is about 150g and about the size of your palm), it receives more blood (20-25% of the cardiac output) than all other organs except the liver. This demonstrates the importance of the dustman role.

4. Two simple tests can detect most cases of kidney disease – a blood test (creatinine/glomerular filtration rate (GFR)) and a urine test (urine Albumin-Creatinine Ratio, ACR).

5. Kidneys generate Vitamin D in the body. Even though this is primarily done by the skin on exposure to sunlight, the kidneys have an important role, especially in winter.