Your urologist may recommend that you have a kidney biopsy. A biopsy involves collecting small pieces of tissue which are sent to a lab for analysis and provides information about the best course of treatment. A pathologist will examine the kidney tissue samples for unusual deposits, scarring, or infection. If you have progressive kidney failure, the test may show how quickly the disease is advancing.

A kidney biopsy may be recommended for:

Before the Test

• Tell your nurse or doctor about any medications you are taking or any allergies you may have.
• Do not take aspirin or other blood-thinning medicines for 1 to 2 weeks before the procedure.
• Your urologist will advise you on food and fluid intake before the test.
• Shortly before the biopsy, blood and urine samples will be taken to make sure you don't have a condition that would make doing a biopsy risky.

During the Test

• The patient is fully awake with light sedation.
• A local anesthetic is given before the needle is inserted.
• Patients lie on their stomachs to position the kidneys near the surface of their backs.
• The doctor marks the entry site, cleans the area, and injects a local painkiller.
• For a biopsy using a needle inserted through the skin, the doctor uses a locating needle and x-ray or ultrasound equipment to find the kidney.
• You may be asked to hold your breath as your doctor uses a spring-loaded instrument to insert the biopsy needle and collect the tissue. It only takes about 30 seconds or a little longer for each insertion.
• The spring-loaded instrument makes a sharp clicking noise.
• The doctor may need to insert the needle three or four times to collect the needed samples.
• The entire procedure usually takes about an hour,

After the Test

• You'll lie on your back in the hospital for a few hours.
• Patients who have a transplanted kidney lie on their stomachs.
• The staff will continue to monitor your vital signs.
• Most patients leave the hospital the same day.
• You may notice some blood in your urine for 24 hours after the test.
• Results are usually ready in a few days. Your physician will discuss the results with you.