Having a kidney biopsy

A kidney biopsy is a procedure, where we remove a small sample of tissue from your kidney with a thin needle. We use ultrasound or CT guidance to put this needle accurately into the kidney. The sample is then examined in detail under a microscope.

Preparing for the procedure

You need to have a blood test about 1 week before the kidney biopsy to check your blood clotting. We do this test because there is a higher risk of bleeding after a procedure if your blood is not clotting properly.

Your doctor or clinical nurse specialist explains how to arrange the blood test when they recommend a kidney biopsy.

Here is more guidance about how to prepare for your kidney biopsy procedure.

Giving your permission (consent)

We want to involve you in decisions about your care and treatment. If you decide to have a kidney biopsy, we will ask you to sign a consent form. This says that you understand what is involved and agree to have the treatment.

You can read more about our consent process.

On the day of the procedure

You usually come into hospital on the morning of the biopsy. Please arrive 15 minutes before your appointment time. This is to allow enough time to prepare.

In the interventional radiology (IR) department, a doctor or nurse checks that your medical condition has not changed since your last visit. We put a small plastic tube (cannula) into your arm. This means that we can give you medicine called a sedative to make you sleepy during the procedure, if needed.

You can ask the IR doctor any questions that you have. We ask you to sign the consent form confirming that you agree to have the biopsy.

During the procedure

An IR doctor does the procedure using an ultrasound machine or CT scanner to see your kidney during the biopsy.

What happens during the procedure

1. We ask you to lie on your tummy.
2. We clean the skin on your back, just below the ribs, with an antiseptic solution. Then we cover this area with sterile towels.
3. We inject a local anaesthetic medicine around the area where we are doing the biopsy. This means that you are awake for the procedure, but the area is numb and you do not feel pain.
4. We put more local anaesthetic medicine into the muscles of your back.
5. When the skin and tissues are completely numb, the IR doctor uses the ultrasound machine or sometimes the CT scanner to find your kidney.
6. The IR doctor removes a small sample of tissue from your kidney with a thin needle.
7. We usually ask you to take in a breath and hold it for a few seconds during the biopsy. This is because the kidneys move slightly when you breathe in and out. You may need to repeat the process a few times to make sure that the IR doctor takes a large enough sample.
8. When the procedure is finished, we send the sample to a laboratory to be examined under a microscope.
9. We clean the wound site and put a dressing over it.

If you have a biopsy of a transplant kidney, we ask you to lie on your back. We put local anaesthetic medicine into the skin and the tummy muscles that sit over the transplant. Then, we do the biopsy in the same way.

How the procedure feels

The test should not be painful. You might feel a little pressure when the IR doctor takes the biopsy with a needle.

The position that you need to lie in during the biopsy might be uncomfortable for a short time.

If you have any pain during the procedure, please tell the nurse. They can give you pain medicine.

You might have some pain or discomfort after the biopsy. You can take your usual painkillers or simple painkillers like paracetamol for the first day. It is important to follow the instructions on the packet.