The first sign of kidney damage is protein in the urine, which a doctor can measure in microscopic amounts, called microalbuminuria. Small amounts of albumin show up in the urine 5 to 10 years before major kidney damage happens.
If you have diabetes, your doctor will suggest regular monitoring of urine and blood tests to check the health of your kidneys.
Occasionally, a doctor may be concerned that kidney injury in a diabetic person is related to a separate problem. In that case, other tests such as ultrasound or a kidney biopsy may be recommended. In a biopsy, a small piece of kidney tissue is removed through a needle and examined in a laboratory.