Private kidney function blood test
Kidney function testing measures how well your kidneys filter waste and regulate electrolyte balance. Includes creatinine, eGFR, urea and electrolytes — available as part of our private health check packages at our Kingston and Crawley clinics, with no fasting required.
No GP referral needed — book directly online
What it checks
What does a kidney function blood test check?
A kidney function blood test (sometimes called U&Es — urea and electrolytes) measures waste products and electrolytes regulated by the kidneys. Together, these markers help assess how well your kidneys are filtering and supporting electrolyte balance.
Our kidney function panel includes 4 markers in Essential and Advanced (Sodium, Urea, Creatinine, eGFR), with Potassium added in our Optimal and Cancer Marker checks for a fuller electrolyte picture.
- Sodium
- Potassium (selected packages)
- Urea
- Creatinine
- eGFR (Estimated Glomerular Filtration Rate)
Which packages include it
Kidney function testing in our packages
Kidney function testing is included in every one of our health check packages — the Optimal and Cancer Marker checks add Potassium for a more comprehensive electrolyte panel.
Advanced
£155
Includes Sodium, Urea, Creatinine, eGFR — plus full blood count and ECG.
Optimal
£189
Adds Potassium for a fuller electrolyte picture, alongside thyroid, hs-CRP inflammation and uric acid.
Men’s Cancer Marker Check
£249
Includes the full kidney and electrolyte panel (Sodium, Potassium, Urea, Creatinine, eGFR) alongside PSA prostate testing and FIT bowel screening.
Women’s Cancer Marker Check
£249
Includes the full kidney and electrolyte panel (Sodium, Potassium, Urea, Creatinine, eGFR) alongside CA125 testing and FIT bowel screening.
Single blood tests start from £99, with some specialist tests priced higher. For better value, many patients choose a health check package instead, which includes a broader blood panel, on-the-day checks and a clearer picture of their results.
What results may indicate
Understanding kidney function results
Kidney markers are most meaningful when read together. Hydration, exercise, diet and certain medications can all affect individual results.
Creatinine and eGFR
Creatinine is a waste product filtered out by the kidneys. eGFR is calculated from creatinine and gives an estimate of how well the kidneys are filtering. Lower eGFR can flag patterns linked to reduced kidney function.
Urea
Urea is another waste product filtered by the kidneys. Levels can be affected by hydration, diet and protein intake as well as kidney function — most useful when read alongside creatinine and eGFR.
Sodium and potassium
Sodium and potassium are electrolytes regulated by the kidneys. Out-of-range levels can flag patterns linked to kidney issues, hydration, certain medications or other underlying conditions. Potassium is included in selected packages.
Kidney function blood tests are for screening and risk awareness, not diagnosis. If results suggest medical follow-up — or if you have current symptoms — please speak to your GP, who can arrange repeat testing or further investigation.
How it works
How private blood testing works
- 1
Choose your package
Pick the blood test panel and health check level that suits your needs.
- 2
Book Kingston or Crawley
Choose your clinic and appointment time online.
- 3
Attend your appointment
Your Health Adviser takes your blood sample and completes your on-the-day checks.
- 4
Receive your report
Blood results are usually ready within 2–5 working days, with clear explanations and next-step guidance.
Where we test
Kingston and Crawley clinics
Rated 5.0 on Google from 48 reviews
Patients regularly mention feeling relaxed, reassured and clearly guided throughout their health check.
“Really nice guy. I felt very at ease and it was a smooth process. Joe gave me insight into my diet that I hadn't considered before which I found very helpful. Definitely recommend!”
“I had an excellent experience for my first appointment. Joe was welcoming and took the time to explain each step clearly, which made the appointment feel relaxed and reassuring. The overall level of care was outstanding.”
“Super happy with the health screening experience. Joe was welcoming, friendly and gave lots of great tips about my health. Highly recommend, I will definitely be back!!”
“Highly recommended. The whole process is simple and smooth. Joe was professional and friendly, who also gave some general health advice. Definitely worth it.”
“My practitioner was very professional and friendly. The health screening was conducted in the way it was described beforehand, and all the tests were completed as expected. I would recommend the service.”
“I recently had a health screening and was thoroughly impressed from start to finish. Joe immediately made me feel at ease. The entire appointment was extremely well organised and professional, yet never felt rushed. I couldn't recommend Optimum Health Screening highly enough.”
FAQ
Kidney function blood test — frequently asked questions
Do I need a GP referral for a kidney function blood test?
Do I need to fast before a kidney function test?
What does a kidney function blood test include?
How quickly will I get my kidney function results?
What if my kidney results are abnormal?
Can I just book a kidney function test on its own?
Related blood tests
Other health markers often checked alongside this test
Ready to book a kidney function blood test?
Choose a health check package at our Kingston or Crawley clinics, with no GP referral needed and results in 2–5 working days.
Or call 020 8058 7765