This 3D animation from The Human Atlas explains Diabetic Nephropathy.

The kidneys are a pair of small, bean-shaped organs located towards the back of the torso, behind the lower ribs. Although people are born with a pair of kidneys, the body can still function efficiently with just one healthy kidney.

The functions of the kidneys include balancing the body's fluid content, regulating blood pressure and red blood cell production and filtering wastes from the body. Each kidney is composed of about one million filtering units called nephrons. Each nephron contains a twisted mass of small blood vessels called glomeruli. The semi-permeable glomeruli allow water and soluble wastes from the blood to pass through the membrane. The filtered wastes are then transported out of the body in the form of urine.

Diabetes is a disorder caused by an excessive amount of glucose, or blood sugar, in the bloodstream, which can damage the membrane and lead to high blood pressure. This increase in blood pressure causes the kidneys to filter too much blood, overworking and damaging the nephron. This condition is known as diabetic nephropathy. Because the nephron's glomeruler filters no longer work, waste begins building up in the body when it should be filtered out, and important blood proteins that should be retained are lost.

Symptoms of this disorder often do not appear until 80 percent of the kidneys have been damaged. When they do appear, symptoms often include swelling, fatigue, loss of appetite, high blood pressure, excessive urination and excessive thirst.

When 85 to 90 percent of kidney function is lost, the term "end stage kidney failure" is used, and kidney dialysis or transplant becomes necessary. About 10 to 20 percent of all diabetics will develop nephropathy, but a healthy lifestyle can delay or even prevent the condition. This includes carefully controlling glucose levels, staying active, keeping blood pressure in a healthy range and maintaining a healthy weight.