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 (hematuria) 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

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:

• Bleeding. The most common complication of a kidney biopsy is blood in the urine (hematuria). The bleeding usually stops within a few days. Bleeding that’s serious enough to require a blood transfusion affects a very small percentage of people who have a kidney biopsy. Rarely, surgery is needed to control bleeding.
• Pain. Pain at the biopsy site is common after a kidney biopsy, but it usually lasts only a few hours.
• Arteriovenous fistula. If the biopsy needle accidentally damages the walls of a nearby artery and vein, an abnormal connection (fistula) can form between the two blood vessels. This type of fistula usually causes no symptoms and closes on its own.
• Others. Rarely, a collection of blood (hematoma) around the kidney becomes infected. This complication is treated with antibiotics and surgical drainage. Another uncommon risk is development of high blood pressure related to a large hematoma.

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.

Medications

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.

After the procedure

After the biopsy, you can expect to:

• Spend time in a recovery room where your blood pressure, pulse and breathing will be monitored.
• Have urinalysis and complete blood count tests done to check for bleeding and other complications.
• Rest quietly for several hours.
• Receive written instructions about your recovery.
• Feel some soreness or pain at the biopsy site for a few hours. You’ll be given medications to relieve pain.

You may need to rest in bed for 12 to 24 hours after the biopsy, as directed by your doctor. 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:

• Significant bright red blood or clots in your urine more than 24 hours after the biopsy
• Inability to pass urine
• Worsening pain at the biopsy site
• Fever over 100.4 F (38 C)
• Faintness or weakness

Expect your biopsy report from the pathology lab within about a week. In urgent situations, a full or partial report may be available in less than 24 hours. At a follow-up visit, your doctor will discuss the results. The results may further explain what’s causing your kidney problem, or they may be used to plan or change your treatment.