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Nutrition and Energy

Kidney Function Blood Test

Brooksby Medical test kit

Your kidneys filter around 180 litres of blood every day, clearing waste and keeping your salts and fluid in balance. This test measures urea, creatinine and eGFR alongside sodium and chloride, giving a clear read on how well they are working. Early kidney disease is usually silent, so it is worth considering if you have high blood pressure or diabetes, a family history of kidney problems, or take regular anti-inflammatory painkillers.

From £37
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Free tracked deliveryResults in 2–3 working daysConvenient testing optionsActionable next stepsDoctor-written reportAccredited UK labsCQC registered
What's measured

What you actually get in this test

5 biomarkers, analysed by a UKAS-accredited UK laboratory and personally reviewed by Dr Coleman.

✓Creatinine
✓estimated GFR (eGFR)
✓Urea
✓Sodium
✓Chloride
Included with every test

A doctor-written report.

Doctor-written reports, with an optional opportunity to discuss your results with a doctor.

  • Your blood test — processed by a UKAS-accredited UK laboratory.
  • A doctor-written report — your results reviewed personally by Dr James Coleman, a practising GMC-registered GP, and explained in plain English.
  • Clear next steps — what your results may mean, and what to do next where appropriate.
  • Optional GP appointment — want to talk it through? You can book a private appointment to discuss your results.
Order my Kidney Function Blood Test — £37
Order your test

Choose how you'd like your sample taken

Pick the option that suits you. The test is the same. Only the way we collect your sample changes.

Kidney Function Blood Test
Total
£37
  • Doctor-reviewed report
  • Free tracked delivery
  • Results in 2–3 working days
  • Actionable next steps
How would you like your sample taken?
Most popular
Self-arrange a professional sample collection
Venous collection kit posted to your door. Take it to your own phlebotomist or nurse, then return the sample in the prepaid envelope.
Included
Book a venous draw at home with a nurse
A qualified phlebotomist comes to you at a time that suits.
+£65
Book a venous draw at a clinic
70+ UK locations (Superdrug). Professional venous draw in about 10 minutes.
+£40
Add more tests to the same sample (optional)
Total£37
We accept
Kidney Function Blood Test £37Doctor's report in 2–3 days
Order
Dr James Coleman
Your doctor

Dr James Coleman

BSc, MB ChB, MRCGP · Practising GP · Founder, Brooksby Medical
“Every Brooksby report is written personally. You get a plain-English interpretation and a clear next step — not just numbers on a page.”
How it works

Simple from start to finish

1

Order your test

Choose online in minutes. Your kit is dispatched and on its way to you.

2

Collect your sample

Venous collection

3

Post it back

Drop your pre-paid, tracked envelope in any postbox. We take it from there.

4

Your doctor-written report

Reviewed by a practising doctor. Delivered to your secure portal within 2–3 working days.

5

Follow-up if you need it

If anything in your report needs discussing, you can request a follow-up with our GP from your account — free, and entirely optional.

You get an explanation, not just a number

Your results, explained in a written report

Brooksby MedicalDoctor Reviewed
Dr J. Coleman has reviewed your Kidney Function Blood Test. Your report explains what each marker means and what (if anything) would make sense to do next.
✓ Result reviewed
Creatinine
—your value
Doctor's note: Your actual report includes a personal interpretation of every marker. If anything sits outside the reference range, we tell you clearly what it means and what — if anything — to do about it.
Illustrative example. Your report will show real values and commentary.
Why Brooksby

A GP-led service from start to finish

🩺

Written interpretation, not a PDF

Your results come with Dr Coleman's written interpretation — what each marker means and what to do about it, in plain English.

📝

doctor-written report included

Every report is written by Dr Coleman, a practising GP — not auto-generated and not outsourced.

👤

A named doctor, not a team

Your report is signed by Dr Coleman personally. Not an anonymous review pool.

🔬

UKAS-accredited UK lab

Recognised clinical laboratory standards (ISO 15189). Consistent, reliable analysis.

💳

One-off, no subscription

You order the test, you get the report, you own the data. No ongoing fees.

Common questions

Everything you need to know before ordering your Kidney Function Blood Test.

What does the Kidney Function Blood Test measure?

This test checks 5 key markers of kidney health: Urea, Creatinine, eGFR (estimated glomerular filtration rate), Sodium and Chloride. Creatinine and eGFR show how well your kidneys are filtering, urea reflects waste clearance and hydration, and the electrolytes show how well your body is balancing salts and fluid.

Who should consider a kidney function test?

This test is useful for:

  • Anyone with high blood pressure or diabetes

  • Those with a family history of kidney disease

  • People who regularly take anti-inflammatory painkillers such as ibuprofen or naproxen

  • Anyone using creatine or high-protein supplements who wants a baseline

  • Those wanting a routine health check alongside cholesterol and blood sugar

Do I need to fast for a kidney function test?

No fasting is required. You can eat and drink normally before this test. Drink water as usual, as being dehydrated can nudge urea and creatinine upwards, and avoid a heavy workout in the 24 hours beforehand.

What can cause abnormal kidney results?

A mildly raised creatinine or lower eGFR can reflect dehydration, a high muscle mass, recent intense exercise, creatine supplements or certain medicines, as well as true kidney disease. eGFR is an estimate calculated from your creatinine, age and sex, so a single result is interpreted in context. Your GP report will explain what your results mean and whether a repeat test or further investigation is needed.

How will I receive my results?

Secure online results with a GP-written explanation from Brooksby Medical in 2 to 3 working days.

More about Brooksby

Is my report reviewed by a doctor?

Yes. Every Brooksby test comes with a written report from Dr James Coleman, a practising GMC-registered GP, who personally reviews your results in the context of your symptoms and explains what each marker means and what to do next. If anything in your report needs discussing, you can request an optional free follow-up from your account — though many people are happy with the written report alone.

How accurate are the results?

Your samples are processed in a UKAS-accredited UK laboratory (ISO 15189, no. 10641). Most of our tests fall within that accreditation; a small number of specialist assays are internally validated while accreditation is being extended to them. Your results are then personally reviewed by a qualified GP before your report is issued.

Who writes the reports?

Every report is written by Dr James Coleman, an experienced, GMC-registered GP — not generated by AI or written by non-medical staff.

How long do results take?

Most reports are ready within 2–3 working days of your sample arriving at the lab. You will receive an email when your report is ready in your secure portal.

Do I need a GP referral?

No. You can order directly without a referral. Brooksby Medical is a CQC-registered service, and every result is reviewed by a practising doctor.

Can I share my results with my GP?

Absolutely. Your report is designed to be shared with any healthcare professional. Many of our patients bring their Brooksby report to their GP appointment for further discussion.

What happens if something is abnormal?

Your doctor-written report explains any results that fall outside the normal range, with clear explanations and recommended next steps. For significantly abnormal results, we'll contact you directly.

What is the difference between venous and fingerprick?

Fingerprick tests use a small lancet to collect drops of blood at home. Venous tests are drawn from a vein by a nurse or phlebotomist. Each test page specifies which is required.

Is my data kept private?

Yes. All data is handled in accordance with UK GDPR. Packaging is plain with no indication of contents. Results are sent securely to you and are never sold. We don't share them with anyone else without your consent, other than where we are legally or professionally required to (for example, public-health reporting or safeguarding).
The Briefing

Learn more in The Briefing

GP-written articles on the conditions and markers behind tests like this one — published in Brooksby Medical's editorial section.

Browse The Briefing →
Still have questions?

Drop us a message — a real person will reply.

We usually get back within one working day. Anything you want to ask before ordering — collection, what's included, fasting, your report, results timing — go ahead.

Your message goes to enquiries@brooksbymedical.com. We'll reply by email — usually within one working day.

From £37 · Doctor-written report included · Results in 2–3 working days

Ready to order?

A simple sample, a UKAS-accredited lab, and a doctor-written report personally interpreted by Dr Coleman.

Order my Kidney Function Blood Test →