A biopsy is done to remove tissue or cells from the body for exam under a microscope. The tissue sample is removed with a needle to check for cancer or other abnormal cells. It also helps check how well the kidney is working.

There are two types of kidney biopsies:

• Needle biopsy. After an anesthetic is given, the doctor inserts the biopsy needle into the kidney to get a sample. Ultrasound or CT scan may be used to guide the needle. Most kidney biopsies are done using this method.
• Open biopsy. After an anesthetic is given, the doctor makes a cut (incision) in the skin and surgically removes a piece of the kidney.

If your doctor wants to sample a certain part of the kidney, the biopsy may be guided by ultrasound, fluoroscopy, or CT.

Your kidneys are a pair of purple-brown organs. They sit below the ribs toward the middle of the back. The kidneys:

• Remove liquid waste from the blood in the form of urine.
• Keep a balance of salts and other substances in the blood.
• Produce a hormone (erythropoietin) that helps form red blood cells.
• Regulate blood pressure.

When your kidney function is abnormal, a kidney biopsy may be done to:

• Find out the reason for poor kidney function.
• Check how well a transplanted kidney is working.

There may be other reasons for your doctor to advise a kidney biopsy.

As with any procedure, complications can happen, including:

• Bruising and mild pain at the biopsy site.
• Ongoing bleeding from the biopsy site, in the urine, or inside the body.
• A hole (puncture) in nearby organs or structures.
• Infection near the biopsy site.

If the kidney biopsy is done with the aid of X-ray, the amount of radiation used is small. This means the risk for radiation exposure is low.

If you are pregnant or think you may be, tell your doctor. Talk with your doctor about the risks to the baby from being exposed to an X-ray. Pregnancy doesn't always mean you can't have a kidney biopsy. It may be important for your health. Special safety steps may be taken to protect both you and the baby during a kidney biopsy.

You may not be able to have a kidney biopsy if you have an active kidney infection, certain bleeding conditions, uncontrolled high blood pressure, or only one working kidney.

There may be other risks depending on your specific health condition. Talk about any concerns with your doctor before the procedure.

• Your doctor will tell you about the procedure, and you can ask questions.
• You will be asked to sign a consent form that gives your permission to do the kidney biopsy. Read the form carefully and ask questions if something isn't clear.
• Your doctor may do a physical exam to be sure you are in otherwise good health. You may have blood tests or other diagnostic tests.
• Tell your doctor if you are sensitive to or allergic to any medicines, latex, tape, or anesthesia.
• Tell your doctor about all medicines (prescribed and over-the-counter) and any vitamins or herbal supplements that you are taking.
• Tell your doctor if you have a history of bleeding disorders or if you are taking any blood-thinning (anticoagulant) medicines, aspirin, or other medicines that affect blood clotting. You may need to stop these medicines before the procedure.
• If you are pregnant or think you might be, tell your doctor before the procedure.
• Follow any directions you are given for not eating or drinking before the biopsy. Your health care team will give you specific instructions.
• You may get a sedative before the procedure to help you relax. Because the sedative may make you drowsy, you will need to arrange for someone to drive you home.
• Based on your health condition, your health care team may request other specific preparations.

A kidney biopsy may be done on an outpatient basis or in a hospital. It may be done in a procedure room, in a hospital bed, or in the radiology department. Procedures may vary depending on your condition and your doctor's practices.

Generally, a kidney needle biopsy follows this process:

1. You will remove your clothing and put on a hospital gown.
2. An I.V. (intravenous) line may be started in your arm or hand.
3. You will lie on your stomach so that the doctor can easily reach the kidney. A pillow may be used to hold you in the right position. If you have a transplanted kidney, you will lie on your back.
4. The skin over the biopsy site will be cleaned with an antiseptic solution.
5. You will feel a needle stick when the local anesthetic is injected. This may cause a brief stinging feeling.
6. You will need to lie still during the procedure.
7. Ultrasound or X-ray may be used to guide the needle into the kidney.
8. You will be asked to breathe in and hold your breath while the doctor inserts the biopsy needle into the kidney. This prevents movement of the diaphragm, which may interfere with the placement of the biopsy needle.
9. You may feel mild pain or pressure when the doctor takes the sample.
10. There may be more than one puncture if the doctor needs more than one tissue sample. If so, the same puncture process will be repeated.
11. When the needle is removed, firm pressure will be applied to the biopsy site to stop bleeding.
12. A sterile bandage or dressing will be applied.
13. The kidney tissue sample will be sent to the lab for testing.

Your recovery will vary depending on the type of procedure done and your doctor's practices. You may be taken to the recovery room and watched closely as the anesthesia wears off. Once your blood pressure, pulse, and breathing are stable and you are alert, you may be taken to a hospital room or discharged to your home.

You will be asked to lie on your back for several hours. A nurse will check your urine for signs of bleeding. You may have blood tests to check for internal bleeding. You may be discharged later the same day or the next day. If you had a sedative or anesthetic, plan to have someone drive you home.

The biopsy site may be tender or sore for several days after the biopsy. Take a pain reliever for soreness as advised by your health care team. You may be told to not take aspirin or certain other pain medicines that may raise the chance of bleeding. Be sure to take only advised medicines.

Tell your health care team if you have any of the following:

• Blood in your urine after the first 24 hours
• Inability to urinate
• Fever or chills
• Redness, swelling, or bleeding or other drainage from the biopsy site
• Increased pain around the biopsy site or elsewhere
• Feeling faint

You may get back to your normal diet unless told otherwise. Your health care team may ask you to rest for a day or two. Don't do strenuous physical activity for several days. Don't do any type of “bouncing" activities, such as jogging, aerobics, playing tennis, or horseback riding for a couple of weeks to prevent bleeding of the biopsy site.

Your doctor may give you other instructions after the procedure, depending on your situation.

Before you agree to the test or the procedure, make sure you know:

• The name of the test or procedure.
• The reason you are having the test or procedure.
• What results to expect and what they mean.
• The risks and benefits of the test or procedure.
• What the possible side effects or complications are.
• When and where you are to have the test or procedure.
• Who will do the test or procedure and what that person's qualifications are.
• What would happen if you did not have the test or procedure.
• Any alternative tests or procedures to think about.
• When and how you will get the results.
• Who to call after the test or procedure if you have questions or problems.
• How much you will have to pay for the test or procedure.