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.
A kidney biopsy may be done to:
Your doctor may recommend a kidney biopsy based on the results of blood or urine tests that show:
Not everyone with these problems needs a kidney biopsy. The decision is based on your signs and symptoms, test results, and overall health.
In general, percutaneous kidney biopsy is a safe procedure. Possible risks include:
Before your kidney biopsy, you'll meet with your doctor to talk about what to expect. This is a good time to ask questions about the procedure and make sure you understand the benefits and risks.
When you meet with your doctor, bring a list of all medications you take, including over-the-counter medications, vitamins and herbal supplements. Before your kidney biopsy, you'll be asked to stop taking medications and supplements that can increase the risk of bleeding. These include:
Your doctor or nurse will let you know when to stop taking these medications and supplements, and for how long. Often, these medications are stopped seven days before the procedure and then started again seven days after the procedure.
Before your biopsy, you'll have blood drawn and provide a urine sample to make sure you don't have an infection or another condition that would make the biopsy risky.
You may be asked not to drink or eat for eight hours before the kidney biopsy.
You'll have a kidney biopsy at a hospital or outpatient center. An IV will be placed before the procedure starts. Sedatives may be given through the IV.
During the biopsy, you'll be awake and lie on your abdomen or your side, depending on which position allows best access to your kidney. For a biopsy of a transplanted kidney, most people lie on their backs.
A percutaneous biopsy includes these steps:
Percutaneous kidney biopsy isn't an option for some people. If you have a history of bleeding problems, have a blood-clotting disorder or have only one kidney, your doctor may consider a laparoscopic biopsy.
In this procedure, your doctor makes a small incision and inserts a thin, lighted tube with a video camera at its tip (laparoscope). This tool allows the doctor to view your kidney on a video screen and remove tissue samples.
After the biopsy, you can expect to:
Most people can leave the hospital the same day, about 12 to 24 hours after the procedure. Once home, your doctor will probably recommend that you rest for another day or two. Your health care team will let you know about any activity restrictions, such as avoiding heavy lifting and strenuous exercise.
Your kidney tissue goes to a lab to be examined by a doctor who specializes in diagnosing disease (pathologist). The pathologist uses microscopes and dyes to look for unusual deposits, scarring, infection or other abnormalities in the kidney tissue.
Call your doctor if you experience:
It may take up to a week before your doctor has your biopsy report from the pathology lab. In urgent situations, a full or partial report may be available in less than 24 hours.
Your doctor will usually discuss the results with you at a follow-up visit. The results may further explain what's causing your kidney problem, or they may be used to plan or change your treatment.