🫘 Kidney Disease (CKD)

Lab Tests for Kidney Disease (CKD)

Chronic kidney disease (CKD) is silent in its early stages — many people have lost significant kidney function before symptoms appear. Blood and urine tests detect it early, track progression, and guide treatment to slow the decline.

Clinician-Reviewed 23 tests covered
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Clinical overview

The kidneys filter 180 litres of blood per day. When they're damaged, waste products accumulate and electrolyte balance is disrupted. eGFR is the key measure — below 60 mL/min for 3+ months defines CKD. Urine albumin reveals damage to the filtration barrier even before eGFR falls.

What to expect

  • 🌅 Morning urine (first void) gives the most accurate ACR result.
  • ⏰ Blood tests for kidney function require no fasting.
  • 💊 Some medications (NSAIDs, ACE inhibitors, aminoglycosides) affect results — mention all medications.
  • 📊 eGFR and ACR together define CKD stage more accurately than eGFR alone.
  • 🔄 CKD diagnosis requires two tests at least 3 months apart.

Testing frequency

Annually
Diabetes or hypertension (CKD screening) eGFR, urine ACR
Every 3–6 months
CKD stages 3–5 eGFR, electrolytes, haemoglobin, phosphorus
Every 1–2 months
CKD stage 4–5 or rapidly declining eGFR Full metabolic panel + PTH
Post-contrast
After IV contrast imaging Creatinine at 48 hours
Additional Tests

Also commonly ordered

These tests are frequently added to the primary panel based on initial results or specific clinical circumstances.

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Urine ACR (Albumin:Creatinine)

The most sensitive early marker of kidney damage — detects proteinuria before dipstick.

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Cystatin C

More accurate than creatinine for estimating GFR, especially in muscle wasting or obesity.

🧪

Uric Acid

Elevated in CKD. Gout is common. Uric acid-lowering therapy protects kidney function.

⚗️

Phosphorus

Rises as CKD advances — secondary hyperparathyroidism and vascular calcification risk.

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CBC

CKD causes anaemia (reduced EPO). Haemoglobin falls as eGFR declines.

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PTH

Parathyroid hormone rises in CKD — secondary hyperparathyroidism damages bones and vessels.

Red Flags

Urgent result thresholds

These result patterns require prompt clinical attention — always discuss with your doctor rather than interpreting alone.

⚠️
eGFR < 15 Urgent

Kidney failure (stage 5 CKD). Renal replacement therapy planning — dialysis or transplant.

🚨
K⁺ > 6.5 mEq/L Emergency

Severe hyperkalaemia — cardiac arrhythmia risk. Emergency management required.

⚠️
eGFR falling > 5/year Urgent

Rapidly progressive CKD — nephrology referral needed urgently.

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ACR > 300 mg/g Watch

Severe proteinuria (macroalbuminuria) — significant CKD progression risk.

Medical Disclaimer: This guide is for educational reference only. It does not constitute medical advice and should not replace consultation with a qualified healthcare professional. Always discuss your test results with your doctor. Full disclaimer →