Your CKD lab report tracks kidney function through a panel of biomarkers — each telling a specific story. eGFR and UACR determine your CKD stage and risk. Serum potassium flags hyperkalemia risk and medication adjustments. Bicarbonate indicates metabolic acidosis. PTH reveals secondary hyperparathyroidism. Haemoglobin signals anaemia of CKD. Understanding each value helps you manage your care proactively.
| Test | Normal Range | CKD Concern | Urgent Action Threshold |
|---|---|---|---|
| eGFR (mL/min/1.73m²) | ≥ 90 | < 60 for >3 months = CKD | < 15 = Kidney failure; dialysis evaluation |
| Serum Creatinine (mg/dL) | F: 0.5–1.1; M: 0.7–1.3 | Rising trend (even within range) | >30% rise within 4 weeks = suspect RAS |
| UACR (mg/g, spot urine) | < 30 | 30–300 (A2 microalbuminuria) | > 300 (A3) = high-risk; initiate RAASi |
| Serum Potassium (mEq/L) | 3.5–5.0 | 5.0–5.5 = mild hyperkalemia | ≥ 6.0 = cardiac emergency; ECG urgently |
| Serum Bicarbonate (mEq/L) | 22–29 | < 22 = metabolic acidosis | < 18 = urgent bicarbonate supplementation |
| Serum Phosphate (mg/dL) | 2.5–4.5 | > 4.5 = hyperphosphatemia | > 5.5 (dialysis patients) = phosphate binder |
| Serum Calcium (mg/dL) | 8.5–10.5 | < 8.5 (hypocalcemia in CKD) | < 7.5 = symptomatic tetany risk |
| PTH (Intact) (pg/mL) | 15–65 | Elevated in G3+ CKD (2HPTH) | G4: target 70–110; G5 dialysis: 150–600 |
| Haemoglobin (g/dL) | F: 12–16; M: 13.5–17.5 | < 12 (anaemia of CKD from G3) | < 10 = ESA therapy consideration |
| Uric Acid (mg/dL) | < 6.0 | > 7 in CKD = worse outcomes | > 9 with gout symptoms = urate-lowering therapy |
| HbA1c (% — diabetic CKD) | < 7.0% | > 7.0 with CKD = increase CVD risk | Target 6.5–8.0% depending on G4–G5 risk of hypoglycemia |
eGFR is the primary staging number for CKD. Calculated using the CKD-EPI 2021 race-neutral formula from serum creatinine, age, and sex, it estimates how many mL of blood your kidneys filter per minute. An eGFR below 60 for more than 3 months confirms CKD. The trend over time is more important than any single value. For full detail, see the eGFR guide.
UACR (urine albumin-to-creatinine ratio) detects protein leaking from damaged kidney filters (glomeruli). Even patients with normal eGFR can have A3 albuminuria (>300 mg/g UACR) — meaning high cardiovascular and CKD progression risk. UACR is collected as a spot urine sample (first morning is most accurate). Elevations should prompt RAASi initiation and SGLT2i consideration.
Potassium regulates heart electrical activity. CKD impairs potassium excretion, causing dangerous accumulation. At K+ above 5.5 mEq/L, RAASi and Finerenone must be held. At or above 6.0 mEq/L, the situation becomes a cardiac emergency — peaked T waves on ECG can precede fatal arrhythmia. See the complete potassium management guide.
The kidney normally excretes 1 mEq/kg/day of acid. In CKD, this capacity falls, causing bicarbonate to drop and blood to become acidic (metabolic acidosis). Bicarbonate below 22 mEq/L in CKD G3+ indicates this complication, which accelerates muscle protein catabolism, worsens bone disease, and may independently speed eGFR decline. Treatment is oral sodium bicarbonate. See the metabolic acidosis guide.
As phosphorus accumulates in CKD blood, it stimulates PTH release from parathyroid glands — an attempt to push phosphorus into bones. Chronically elevated PTH causes renal osteodystrophy (fragile bones), vascular calcification, and cardiovascular complications. In CKD G3, target PTH is 35–70 pg/mL. Treatment includes dietary phosphorus restriction and active Vitamin D therapy (calcitriol or alfacalcidol).
What is a normal eGFR reading?
Normal eGFR is 90 mL/min or above without kidney damage markers. Below 60 for more than 3 months = CKD (KDIGO 2024). Below 15 = kidney failure. Trend over time matters more than a single reading.
What is UACR and what does it mean?
UACR measures protein leaking into urine. A1 (<30 mg/g) = normal. A2 (30–300) = microalbuminuria. A3 (>300) = macroalbuminuria — high CKD and cardiovascular risk. UACR combines with eGFR in the KDIGO risk matrix.
What does low bicarbonate mean in CKD?
Bicarbonate below 22 mEq/L indicates metabolic acidosis — the kidney can't excrete enough acid. This causes muscle wasting, bone loss, and faster CKD progression. Treatment: oral sodium bicarbonate supplements to target 23–29 mEq/L (KDIGO 2024).
What does high PTH mean in CKD?
Elevated PTH in CKD indicates secondary hyperparathyroidism from phosphate retention. This causes brittle bones (renal osteodystrophy) and vascular calcification. Treatment: dietary phosphate restriction, phosphate binders, active Vitamin D (calcitriol), and calcimimetics (cinacalcet) in dialysis patients.