A kidney biopsy is a procedure to remove a small piece of kidney tissue that can be examined under a microscope for signs of damage or disease.
Your doctor may recommend a kidney biopsy — also called renal biopsy — to diagnose a suspected kidney problem. It may also be used to see how serious a kidney condition is, or to monitor treatment for kidney disease. You may also need a kidney biopsy if you've had a kidney transplant that's not working properly.
Most often, a doctor performs a kidney biopsy by inserting a thin needle through the skin. This is called a percutaneous kidney biopsy. An imaging device helps the doctor guide the needle into the kidney to remove tissue.

Why it's done

A kidney biopsy may be done to:

• Diagnose a kidney problem that can't otherwise be identified
• Help develop treatment plans based on the kidney's condition
• Determine how quickly kidney disease is progressing
• Determine the extent of damage from kidney disease or another disease
• Evaluate how well treatment for kidney disease is working
• Monitor the health of a transplanted kidney or find out why a transplanted kidney isn't working properly

Your doctor may recommend a kidney biopsy based on the results of blood or urine tests that show:

• Blood in the urine originating from the kidney
• Protein in the urine (proteinuria) that's excessive, rising or accompanied by other signs of kidney disease
• Problems with kidney function, leading to excessive waste products in the blood