Diagnosis

Diabetic nephropathy is usually diagnosed during routine testing that's a part of your diabetes management. If you're living with type 1 diabetes, screening for diabetic nephropathy is recommended beginning five years after your diagnosis. If you are diagnosed with type 2 diabetes, screening will begin at the time of diagnosis.

Routine screening tests may include:

• Urinary albumin test. This test can detect the blood protein albumin in your urine. Typically, the kidneys don't filter albumin out of the blood. Too much of the protein in your urine can indicate poor kidney function.
• Albumin/creatinine ratio. Creatinine is a chemical waste product that healthy kidneys filter out of the blood. The albumin/creatinine ratio — a measure of how much albumin is in a urine sample relative to how much creatinine there is — provides another indication of kidney function.
• Glomerular filtration rate (GFR). The measure of creatinine in a blood sample may be used to estimate how quickly the kidneys filter blood (glomerular filtration rate). A low filtration rate indicates poor kidney function.

Other diagnostic tests may include the following:

• Imaging tests. Your doctor may use X-rays and ultrasound to assess your kidneys' structure and size. You may also undergo CT scanning and magnetic resonance imaging (MRI) to determine how well blood is circulating within your kidneys. Other imaging tests may be used in some cases.
• Kidney biopsy. Your doctor may recommend a kidney biopsy to take a sample of kidney tissue. You'll be given a numbing medication (local anesthetic). Then your doctor will use a thin needle to remove small pieces of kidney tissue for examination under a microscope.