National Kidney and Urologic Diseases Information Clearinghouse: Kidney biopsy

Kidney biopsy – Pamphlet

* Preparation * Test Procedures * After the Test * Getting the Results * For More Information

A biopsy is a diagnostic test that involves collecting small pieces of tissue, usually through a needle, for examination under a microscope. A kidney biopsy can help find a diagnosis and determine the best course of treatment. Your doctor may recommend a kidney biopsy if you have any of the following conditions:

* Hematuria (blood in your urine)

* Proteinuria (excessive protein in your urine)

* Impaired kidney function (excessive waste products in your blood)

A pathologist will look at the kidney tissue samples to check for unusual deposits, scarring, or infecting organisms that would explain your condition. The doctor may discover that you have a condition that can be treated and cured. If you have progressive kidney failure, the biopsy may indicate how quickly the disease is advancing. A biopsy can also help explain why a transplanted kidney is not working properly.

Talk with your doctor about what information might be obtained from the biopsy and the risks involved so that you can help make a decision about whether a biopsy is worthwhile in your case.


You will have to sign a consent form indicating that you understand the risks involved in this procedure, although they are very slight. Discuss these risks thoroughly with your doctor before you sign the form.

Make sure your doctor is aware of all the medicines you take and any drug allergies you might have. You may be told to avoid food and fluids for 8 hours before the test. Shortly before the biopsy, you will give blood and urine samples to make sure you don’t have a condition that would make doing a biopsy less desirable.

Test Procedures

Kidney biopsies are usually done in a hospital. You may be fully awake with light sedation, or you may be asleep under general anesthesia. If you are awake, you will be given a local anesthetic before the needle is inserted.

You will lie on your stomach to position the kidneys near the surface of your back. If you have a transplanted kidney, you will lie on your back. The doctor will mark the entry site, clean the area, and inject a local painkiller. For a percutaneous (through the skin) biopsy, your doctor will use a locating needle and x-ray or ultrasound equipment to find the right spot and then a collecting needle to gather the tissue. You will be asked to hold your breath as the doctor inserts the biopsy needle and collects the tissue, usually for about 30 seconds or a little longer for each pass. Do not exhale until you are told. You may feel a small “popping” sensation as the needle enters the kidney. The doctor may need three or four passes to collect the needed samples.

The entire procedure usually takes about an hour, including time to locate the kidney, clean the biopsy site, inject the local painkiller, and obtain the tissue samples.

After the Test

You should lie on your back for 12 to 24 hours. During this time, your back will probably feel sore. If you have a transplanted kidney, you will lie on your stomach. You will likely stay in the hospital overnight after the procedure so that staff can check your condition. You may notice some blood in your urine for 24 hours after the test. To detect any problems, your team will monitor your blood pressure and pulse, take blood samples to measure the amount of red cells, and examine the urine that you pass. On rare occasions when bleeding does not stop on its own, it may be necessary to replace lost blood with a transfusion.

A rare complication is infection from the biopsy procedure. Tell your doctor or nurse if you have any of these problems:

* Bloody urine more than 24 hours after the test

* Inability to urinate

* Fever

* Worsening pain in the biopsy site

* Faintness or dizziness

After the biopsy, the doctor will inspect the tissue samples in the laboratory under one or more microscopes, perhaps using dyes to identify different substances that may be deposited in the tissue. It usually takes a few days to get the complete biopsy results. If your case is urgent, you may have a preliminary report within a few hours.

Before the Test

* Talk with your doctor to make sure you understand the need for a biopsy.

* Sign a consent form.

* Tell your doctor about any allergies you have and medicines you take.

* Avoid food and fluid for 8 hours before the test. After the Test

* Lie on your back (stomach for an transplanted kidney) for 12 to 24 hours.

* Report any problems such as

** bloody urine more than 24 hours after the test

** inability to urinate

** fever

** worsening pain

** faintness or dizziness

For More Information

For more information, contact

American Kidney Fund

6110 Executive Boulevard, Suite 1010

Rockville, MD 20852

Phone: 1-800-638-8299 or (301) 881-3052



National Kidney Foundation

30 East 33rd Street

New York, NY 10016

Phone: 1-800-622-9010 or (212) 889-2210



National Kidney and Urologic Diseases Information Clearinghouse

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The National Kidney and Urologic Diseases Information Clearinghouse (NKUDIC) is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes of Health under the U.S. Department of Health and Human Services. Established in 1987, the clearinghouse provides information about diseases of the kidneys and urologic system to people with kidney and urologic disorders and to their families, health care professionals, and the public. NKUDIC answers inquiries, develops and distributes publications, and works closely with professional and patient organizations and Government agencies to coordinate resources about kidney and urologic diseases.

Publications produced by the clearinghouse are carefully reviewed by both NIDDK scientists and outside experts. This fact sheet was reviewed by Roger C. Wiggins, M.D., University of Michigan.

This e-text is not copyrighted. The clearinghouse encourages users of this e-pub to duplicate and distribute as many copies as desired.


NIH Publication No. 01-4763


Posted: May 2001

COPYRIGHT 2001 National Kidney and Urologic Diseases Information Clearinghouse

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