Blood urea nitrogen (BUN) test in Chiswick

What the test measures

Urea is made in the liver when protein is broken down, and the kidneys filter it out into the urine. Measuring how much is left in the blood gives an indication of how well the kidneys are clearing waste and of your hydration. In the UK, laboratories usually report urea, while blood urea nitrogen (BUN) is the same measurement expressed as its nitrogen content, the form often used in the United States.

This test reports both, which is useful if you are comparing with results from abroad or following a plan that uses BUN. Urea is most informative when read alongside creatinine and eGFR, which give a more direct picture of kidney filtration.

Your price includes the sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result and a GP feedback report on request.

Who it is for

• You have had a raised or low urea on a previous test and want to recheck it.
• You follow a high-protein diet or train hard and want to see the effect on urea.
• You are comparing with results from overseas that were reported as BUN.
• You take medicines that can affect the kidneys and want a simple check.
• You often feel dehydrated and want an indication of your hydration status.

Understanding your result

Your report shows urea and BUN against the laboratory reference range. A raised level can reflect dehydration, a high-protein diet, bleeding in the upper gut, some medicines or reduced kidney function. A low level is less common and can occur with a low protein intake, pregnancy, overhydration or liver conditions.

Urea alone cannot tell you how well your kidneys are working, so your practitioner may suggest creatinine and eGFR if the result is outside the range. A result outside the range is a prompt for discussion, not a diagnosis.

Preparing for your test

Fasting is not required. Drink water as usual so that you are normally hydrated, and avoid an unusually large high-protein meal the evening before, as this can raise urea for a few hours. Continue your usual medicines unless your doctor has told you otherwise.

For a fuller look at the kidneys, our kidney function tests include creatinine, eGFR and electrolytes. Alternatively, view every blood test and price in Chiswick.

Questions

How much is a BUN blood test in Chiswick?

The Blood Urea Nitrogen (BUN) test costs £59. It includes your blood sample at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review and a GP feedback report on request.

What is the difference between urea and BUN?

They are the same substance reported in different ways. BUN expresses the nitrogen part of urea and is common in the United States, while UK laboratories usually report urea.

Can dehydration raise my urea?

Yes. Being dehydrated is one of the most common reasons for a mildly raised urea, which is why we suggest drinking normally before the test.

Is this enough to check my kidneys?

It is a useful starting point, but creatinine and eGFR give a clearer picture of kidney filtration and are often tested alongside it.