Diabetic nephropathy usually causes no symptoms, and people who have the condition often produce normal amounts of urine. To detect diabetic nephropathy, healthcare providers rely on tests that measure protein levels in the urine and blood tests to evaluate the level of kidney function.

When the kidneys are working normally, they prevent protein from leaking into the urine, so finding protein in the urine is a sign that the kidneys are in trouble. Often people who have diabetic nephropathy also have high blood pressure.