Ultrasound-Guided Kidney Biopsy
What is kidney biopsy?
Kidney biopsy is a procedure that removes a
small piece of the kidney. It is then
examined under a microscope to help your
kidney doctor figure out the cause of the
kidney disease. Results of the biopsy often
take about 7 days.
Why do you need a kidney biopsy?
Kidney biopsy helps to figure out the cause
of kidney disease. It also shows us how
much scarring is in the kidney and how
much of the kidney disease is reversible.
Kidney biopsy is often needed:
ξ If you have protein in the urine
ξ If you have blood in the urine
ξ If your kidneys are not removing
toxins as they should from the blood
How to Prepare at Home
ξ Do not eat or drink after midnight
the night before the procedure.
o Blood thinners such as
Coumadin® (warfarin), heparin,
Plavix, Pradaxa, apixiban or low
molecular heparin injections such
as Fragmin or Lovenox: Do not
take these medicines for 7 days
before the kidney biopsy.
o Please do not take NSAIDS such
as ibuprofen, naproxen, Motrin,
Aleve, aspirin or aspirin-
containing products and fish oil
for 7 days before the biopsy.
o You may take other prescription
medicines with a small sip of
water. This includes blood
o If you have any questions, please
call the Kidney Clinic at (608)
ξ If you have diabetes, please call
your doctor to discuss how your
medicine doses should change.
o Test your blood sugar more often
when you are not eating before
o If your blood sugar level is low
(less than 70 mg/dl) or you have
symptoms, eat some glucose
tablets or drink 4 ounces of a
clear liquid with sugar. Always
recheck your blood sugar level to
make sure it stays above 70
o We may still be able to do the
procedure unless you need to eat
solid food to keep your blood
sugar at a normal level.
o If the blood sugar ever gets too
high or too low and you can’t
bring it back to normal, call your
local doctor or diabetes doctor.
What to Expect on the Day of the Biopsy
ξ Check-in at the UW Hospital Patient
Admissions Office about 3 hours
before your procedure. This will
allow us time to prepare you for your
biopsy. Our doctors will explain
what will happen, answer any
questions, and ask you to sign a
ξ You will get an IV and have blood
tests done. These tests are to make
sure your blood is not too thin and it
is safe to do the biopsy.
ξ Your blood pressure will be checked.
It should be below 140/90 to do the
procedure safely. This is why you
need to take your blood pressure
medicines as prescribed.
During the Biopsy
ξ You will be awake. You may be
given medicines to help you relax if
you are anxious.
ξ You will be taken to Radiology
department. We will look at your
kidneys using ultrasound. You will
be lying on your belly and the doctor
will mark the area for biopsy.
ξ Local anesthetic (numbing medicine)
is used at the site of the biopsy. The
doctor will use ultrasound when
doing the biopsy to avoid big blood
vessels in the kidney.
ξ Doctors will take a small piece of
tissue out of the kidney. You will
have to hold your breath when the
needle is inserted in the kidney. They
will repeat this 2 or 3 times to get
enough tissue sample.
After the Biopsy
ξ After your biopsy, you should expect
to be admitted to UW Hospital
overnight for observation.
ξ You will go back to your hospital
room and will be able to eat.
ξ You must stay in bed for 4 hours
after the biopsy. The nurse will
check your blood pressure and pulse
during this time to make sure they
ξ You might feel some discomfort in
your back after the local numbing
medicine wears off. Let your nurse
know and s/he can give you
something to control pain.
ξ Your doctor will check your blood
counts 4 hours and 8 hours after the
biopsy to make sure they are stable.
ξ You will go home the next morning
if your blood counts are stable and
you are feeling well.
ξ Continue to avoid all blood thinners.
Ask your doctor when you can
restart blood thinners. Restart all of
your other medicines.
ξ You may eat or drink what you like
once you arrive home. Do not drink
alcohol for the first 24 hours.
ξ Rest and take it easy for the first 24
hours. Do not lift more than 10
pounds during this time. Resume
your normal routine after 24 hours.
ξ You may remove the bandage over
the site the next morning.
ξ You may shower after 24 hours.
Risks of Biopsy
ξ Bleeding: You may have blood in
your urine after the biopsy. This is
because kidneys get a lot of blood to
filter. Rarely the bleeding might be
severe and you might need a blood
transfusion. Very rarely you might
need a procedure to stop the
ξ Pain: Usually it is mild and does get
better within 24 hours after the
When to Call the Doctor
Call if you have any other questions or
concerns, or if:
ξ You have more than a teaspoon of
bleeding at the site.
ξ You feel dizzy, faint, or light-
ξ Your pain around the site gets worse
rather than better 2-3 days later.
ξ Severe back pain
ξ You are not feeling well (including
nausea, vomiting, or chills) and have
a fever greater than 100.4°F (38°C).
ξ Blood clots or blood in your urine
that is getting worse after 2 days.
ξ During the day (8:30am – 5:00pm),
call the Kidney Clinic (608) 270-
ξ Evenings and weekends: call your
local doctor or go to your local
Before the biopsy
ξ Ask your doctor why you need
ξ Stop all blood thinners 7 days
prior to biopsy
ξ Take your blood pressure
medicines on the day of biopsy
ξ Do not eat anything after
midnight on the day of biopsy
After the biopsy
ξ Rest and take it easy for the first
ξ Continue to avoid all blood
thinners. Ask your doctor when
you can restart them.
ξ Restart all of your other
ξ Call your doctor if you:
o have trouble passing urine,
o see blood clots in urine,
o have severe back pain, or
o are lightheaded or dizzy.
ξ Do not forget to ask the results of
kidney biopsy (usually takes
about 7 days).
References/Sources of Images
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (2015, November).
Kidney biopsy. Retrieved from https://www.niddk.nih.gov/health-information/diagnostic-
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this information. If you have an emergency, please call 911. Copyright © 09/2017 University of Wisconsin Hospitals
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