Kidney Tests

Kidney tests explained in plain language

Got a lab report with words like creatinine, eGFR or ACR? This is where you find out what each test measures, how to prepare, and which question to ask next. We explain tests; we do not interpret your personal result.

Written by: Mombasa Kidney Care editorial team

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Test directory

Most people in Mombasa get kidney tests from a hospital outpatient clinic or a private lab, then carry the report to a doctor. Start with the test named on your report.

Blood test

Creatinine

A muscle waste product in the blood. Used to estimate kidney filtration, never read on its own.

What it measures Calculated result

eGFR

Estimated filtration rate, worked out from creatinine, age and sex. Grouped as G1 to G5.

What it estimates Urine test

Urine ACR

Finds small amounts of albumin leaking into the urine, often before blood tests change. Grouped as A1 to A3.

Why albumin matters Urine test

Urinalysis

A general urine check with a dipstick and microscope: protein, blood, sugar and signs of infection.

What urine testing reveals Blood panel

Kidney function tests (UECs)

Urea, electrolytes and creatinine on one sample. Also called RFTs or KFTs.

What the panel includes Scan

Kidney ultrasound

Pictures of kidney size and structure. Finds blockages, stones and cysts, but does not measure function.

What the scan shows

Urea and electrolytes

These results usually appear on the same report as creatinine. They are explained in more detail on the kidney function tests page.

Test	What it is	Why it may be checked
Urea	A waste product from the breakdown of protein	Rises when filtration falls, and also with dehydration or a high protein intake
Sodium	The main salt in the blood	Shows the balance of water and salt, which the kidneys help control
Potassium	A mineral that controls muscle and heart signals	The kidneys remove extra potassium. Levels are watched in kidney disease and with some medicines
Chloride and bicarbonate	Salts that help keep the blood's acid level stable	Can change in kidney disease, vomiting or diarrhoea

Reference ranges differ between labs. Always use the range printed on your own report.

Why kidney tests are read together

No single test gives the whole picture. International guidance from KDIGO (Kidney Disease: Improving Global Outcomes, 2024) recommends estimating kidney function as an eGFR using a validated equation rather than relying on a creatinine number alone. It places urine albumin, measured as the ACR, alongside eGFR in every assessment of chronic kidney disease (CKD).

Timing matters too. CKD is only diagnosed when changes last more than 3 months, so one abnormal result is usually repeated. A simple way to remember the core pair:

Blood test (creatinine, then eGFR): how well are the kidneys filtering?
Urine test (ACR): are the kidney filters leaking albumin?
Scan (ultrasound), when needed: what do the kidneys look like?

If you have diabetes or high blood pressure (presha), both eGFR and ACR are usually recommended at regular intervals. See kidney tests for diabetes and monitoring CKD.

Before your next test

Keep every report, from every lab. Trends over time are more useful than one number.
Check the units. Creatinine may be in µmol/L or mg/dL, and ACR in mg/mmol or mg/g.
Tell the lab and your clinician about medicines and supplements you take.
Write down questions to take to your appointment. Our list of questions to ask your doctor can help.
Unfamiliar word on the report? Look it up in the kidney test glossary.

When to get medical help urgently

A test page cannot help in an emergency. Go to the nearest hospital emergency department if you are passing very little or no urine, have severe breathlessness, chest pain or confusion, or if a lab or doctor has told you a result is dangerously abnormal.

Learn moreHigh creatinine Understand your next stepKidney testing in Mombasa Ready for careFind kidney care in Mombasa

Sources

KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. kdigo.org
NICE guideline NG203: Chronic kidney disease: assessment and management. nice.org.uk
National Kidney Foundation. kidney.org

This page explains what a test or condition involves. It is not a diagnosis and does not replace advice from a doctor who knows your history. Your results should be interpreted together with your symptoms, other tests and a clinical assessment. Medical disclaimer.