Your kidneys are quiet, hard-working organs. Every day they filter your entire blood volume many times over, removing waste, balancing salts and fluid, and helping control blood pressure. A kidney function blood test — sometimes called a renal profile or U&E — gives a clear read on how well that filtering is working, usually before any symptoms appear.
What your kidneys do
Beyond filtering waste, the kidneys regulate the balance of water and key salts, help manage blood pressure, and support the production of red blood cells and healthy bones. Because kidney problems often develop silently, a blood test is one of the few practical ways to catch changes early.
The markers in a kidney function test
A standard panel looks at several markers together, each giving a different angle:
- Creatinine — a waste product from normal muscle activity. The kidneys clear it steadily, so a rising level can indicate reduced filtering.
- Urea — a waste product from protein breakdown. It is influenced by diet and hydration as well as kidney function.
- eGFR — the estimated glomerular filtration rate, calculated from creatinine, age and sex. It summarises how well the kidneys are filtering as a single, easy-to-track number.
- Sodium and potassium — electrolytes the kidneys keep in careful balance; abnormal levels can affect nerves, muscles and the heart.
What abnormal results can mean
Results can drift outside the usual range for many reasons, not all of them serious. Dehydration, a high-protein meal, intense exercise and certain medications can all nudge markers temporarily. More persistent changes may point to reduced kidney function, which can be linked to high blood pressure, diabetes, some medicines or, less commonly, kidney disease itself. A single abnormal result usually prompts a repeat test rather than immediate conclusions.
Check your kidney function
A kidney function test checks urea, creatinine, electrolytes and eGFR — a clear picture of how well your kidneys are filtering.
Check your kidney functionWho should consider testing
Kidney checks are especially worthwhile if you:
- have high blood pressure or diabetes, both of which can affect the kidneys over time;
- take regular medication that is processed by or can affect the kidneys;
- have a family history of kidney disease;
- want a baseline as part of a broader health check.
When to get checked
If you have a long-term condition such as high blood pressure or diabetes, periodic kidney testing is a sensible part of monitoring. It is also reasonable to include kidney function in a general health screen. If a result comes back abnormal, do not panic — hydration and timing can influence readings — but do follow it up with a clinician, who can arrange a repeat and interpret the trend properly.
Check your kidney function
Book online with OneMedicine — CQC-registered clinic in Birmingham, or a home visit / local clinic nationwide. Doctor-reviewed results, most within 24 hours.
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Specialist interest: Cardiovascular Medicine · OneMedicine, CQC-registered clinic