Diagnosis

If your signs and symptoms suggest that you have acute kidney failure, your doctor may recommend certain tests and procedures to verify your diagnosis. These may include:

• Urine output measurements. Measuring how much you urinate in 24 hours may help your doctor determine the cause of your kidney failure.
• Urine tests. Analyzing a sample of your urine (urinalysis) may reveal abnormalities that suggest kidney failure.
• Blood tests. A sample of your blood may reveal rapidly rising levels of urea and creatinine — two substances used to measure kidney function.
• Imaging tests. Imaging tests such as ultrasound and computerized tomography may be used to help your doctor see your kidneys.
• Removing a sample of kidney tissue for testing. In some situations, your doctor may recommend a kidney biopsy to remove a small sample of kidney tissue for lab testing. Your doctor inserts a needle through your skin and into your kidney to remove the sample.