Kidney Function Tests: Creatinine, eGFR, and Urine Protein
Kidney disease is usually silent until late. A yearly creatinine and urine test catches it early — when it is still reversible.
Creatinine and eGFR
Creatinine is a waste product of muscle metabolism, cleared entirely by the kidneys. Its blood level depends on muscle mass, age, and sex — so laboratories report an estimated glomerular filtration rate (eGFR), calculated from creatinine and demographic factors, as the standard measure.
Chronic kidney disease is defined by an eGFR under 60 mL/min/1.73 m² for at least three months, or evidence of kidney damage (like proteinuria) at any eGFR. Early stages are asymptomatic — which is why yearly screening matters, especially with diabetes, hypertension, or family history.
Urine protein and albumin
A spot urine albumin-to-creatinine ratio (ACR) detects microalbuminuria — small amounts of albumin leaking into the urine that indicate early kidney damage before eGFR falls. It is the most sensitive early marker in diabetic and hypertensive patients.
Add creatinine and urine ACR to your visit
Ready to book? Reserve a private blood collection appointment on our Book Blood Collection page, or request a private requisition through blood test prescription.
Frequently asked questions
Does hydration affect creatinine?+
Yes — severe dehydration can transiently raise creatinine and lower eGFR. Repeat after normal hydration.
Do muscular adults have higher creatinine?+
Yes, and their eGFR can look artificially low. A cystatin-C measurement can clarify.