Kidneys are two large organs located on either side of your spine, just above the small of your back. Human kidneys look like large purplish brown beans with the hollow side facing inwards.

Healthy kidneys remove wastes from the blood via the urine and return the clean blood back to the body. The kidneys also regulate the levels of water and different minerals needed by the body for good health, and they produce hormones that control other body functions. They regulate the production of red blood cells to avoid anemia and form active vitamin D necessary for normal bone formation. Healthy kidneys retain protein and get rid of waste products, but diseased kidneys do not filter properly and do not retain protein very well, so the presence of protein in the urine is a useful indicator of silent kidney disease.

Many other organs depend on the kidneys in order to work properly. This means that the consequences of kidney disease can affect the whole body. The heart and blood vessels can be damaged and function poorly, and anaemia is also common.