Diagnosis

IgA nephropathy is often detected after you notice blood in your urine or when a routine test shows that you have protein or blood in your urine. These tests can help identify which kidney disease you have:

• Urine tests. Blood or protein in the urine, a possible first sign of IgA nephropathy, might be discovered during a routine checkup. If your doctor suspects that you have problems with your kidneys, you might be asked to collect your urine for 24 hours for additional kidney function tests.
• Blood tests. If you have kidney disease, a blood test might show increased blood levels of the waste product creatinine.
• Kidney biopsy. This procedure is the only way for your doctor to confirm a diagnosis of IgA nephropathy. It involves using a special biopsy needle to extract small pieces of kidney tissue for microscopic examination.
• Iothalamate clearance test. Your doctor may also recommend this test, which uses a special contrast agent to track how well your kidneys are filtering wastes.