Diabetic nephropathy is diagnosed using tests that check for a protein (albumin) in the urine, which is an indicator of kidney damage. Your urine will be checked for protein (urinalysis) when you are diagnosed with diabetes.

Microalbumin urine tests can detect very small amounts of protein in the urine that cannot be detected by a routine urine test, allowing early detection of nephropathy. Early detection is important, to prevent further damage to the kidneys. The results of two tests, done within a 3- to 6-month period, are needed to diagnose nephropathy.

When to begin checking for protein in the urine depends on the type of diabetes you have. After testing begins, it should be done every year.¹

A microalbuminuria dipstick test is a simple test that can detect small amounts of protein in the urine (microalbuminuria, also called proteinuria). The strip changes color if protein is present, providing an estimate of the amount of protein. A spot urine test for microalbuminuria is a more precise laboratory test that can measure the exact amount of protein in a urine sample. Either of these tests may be used to test your urine for protein.

You will also have a creatinine test done every year. The creatinine test is a blood test that shows how well your kidneys are working.

If your health professional suspects that the protein in your urine may be caused by a disease other than diabetes, other blood and urine tests may be done. You may have a small sample of kidney tissue removed and examined (renal biopsy).³

Other tests

It is important to check your blood pressure regularly, both at home and in your health professional's office, because blood pressure rises as kidney damage progresses. About one-third of people with type 2 diabetes have high blood pressure at the time diabetes is diagnosed. The American Diabetes Association recommends a target blood pressure of less than 130/80 millimeters of mercury (mm Hg).¹ The level recommended by other organizations may vary. Talk with your health professional about what your target blood pressure level should be. Keeping your blood pressure at or below this target can prevent or slow kidney damage.

Blood levels of cholesterol and triglycerides also should be checked regularly to see whether diabetes, nephrotic syndrome, or other factors are raising your blood cholesterol level. High cholesterol can increase the risk of hardening of the arteries (atherosclerosis), possibly leading to heart disease, peripheral arterial disease, and stroke.