A renal biopsy is the removal of a small piece of kidney tissue for laboratory examination.

There are many ways of performing a kidney biopsy. The most common uses ultrasound guidance. This means the doctor uses an ultrasound image to located the proper area in your kidney. The biopsy is done in the hospital, usually in the radiology suite. Your doctor will go over the procedure, benefits, and risks in great detail.

You will be expected to lie face down for at least 20-30 minutes. A towel may be placed under your upper abdomen so you remain in the correct position. After finding the proper biopsy site using ultrasound, a local numbing medicine (anesthetic) is applied to the skin near the area.

The health care provider makes a tiny cut in the skin and inserts a biopsy needle into the area and to the surface of the kidney. You will be asked to take and hold a deep breath as the needle is introduced into the kidney. If the health care provider is not using direct ultrasound guidance, he may ask the patient to take deep breaths to verify needle is in place.

The biopsy needle is then withdrawn and pressure is applied to the biopsy site to stop the bleeding. The needle may need to be inserted again (possibly several times) before enough tissue is collected. After the procedure, a bandage is applied to the biopsy site.

You will need to remain in bed for 6-8 hours after the procedure and will be observed in the hospital for a day. The health care team will give you pain medicines and fluids by mouth or a vein. Your urine output will be checked for excessive bleeding. (A little bleeding usually occurs). Blood counts and vital signs are monitored.

Kidney biopsies may also be done using CT scan guidance. Under some circumstances, the biopsy may be performed by running the biopsy catheter through one of the neck veins -- this is called a trans-jugular biopsy.

Tell your doctor if you are pregnant or if you have any drug allergies or bleeding problems. Make sure the health care team knows what medications you are taking.

You may be told to avoid foods or fluids before the test.

The amount of pain during and after the procedure depends on the patient. Because a local anesthetic is used, discomfort during the procedure is usually minimal. The anesthetic may burn or sting when first injected. After the procedure, the area may feel tender or sore for a few days.

You may see bright, red blood in the urine the first 24 hours after the test. If the bleeding lasts longer, tell your health care provider.