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Blood Urea Nitrogen

What is it?

Blood urea (u-ree-uh) nitrogen (ni-tro-jen), or BUN, is a blood test that gives information about your kidneys. Urea is a breakdown product of proteins and is removed from the blood through the kidneys. BUN may tell your caregiver how well your kidneys are working.

Why do I need it?

BUN is usually included with routine laboratory testing. Most kidney diseases cause less urea to be removed through the kidneys. This means more urea will stay in the blood. A normal, high, or low BUN level helps caregivers with your treatment. Conditions other than kidney disease that may change the BUN level are dehydration (d-hi-dra-shun), liver disease, or internal bleeding.

How do I get ready for the test?

Your caregiver will tell you when to have your blood test done. The blood test may be done before or after eating. Your caregiver will tell you if you should not take your medicines until after your blood is taken.

How is the specimen collected?

A caregiver will put a wide rubber strap around your arm and tighten it. Your skin will be cleaned with alcohol. A small needle attached to a special test tube will be put into a vein in your arm or hand. The tube has suction to pull the blood into it. When the tube is full, the rubber strap, needle and tube are removed. The caregiver will press a piece of cotton where the needle was removed. You may be asked to hold the cotton on the site for a few minutes to help stop the bleeding. Tape may then be put over the cotton on your arm.

What do I do after the test?

You may remove the tape and cotton in about 20 to 30 minutes. Call your caregiver to get the results of your test. Your caregiver will explain what your test results mean for you. Follow the instructions of your caregiver.

Care Agreement

You have the right to help plan your care. To help with this plan, you must learn about your lab tests. You can then discuss the results with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.