Chart — Lab Values
Normal Lab Values Chart
Standard adult reference ranges for the lab panels most commonly encountered in nursing practice. Values reflect general adult ranges; always confirm against your institution's laboratory reference values.
Educational use only. Reference ranges vary by laboratory, patient age, sex, and clinical context. This chart is for study and clinical reference — always use your institution's stated reference ranges in clinical settings. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Complete Blood Count (CBC)
| Test | Normal Range | Clinical Note |
|---|---|---|
| WBC | 4,500 – 11,000 /μL | Elevated in infection/inflammation; decreased in neutropenia |
| RBC | M: 4.5–5.9 million/μL F: 4.0–5.2 million/μL | Low in anemia; high in polycythemia vera |
| Hemoglobin (Hgb) | M: 13.5–17.5 g/dL F: 12.0–15.5 g/dL | Critical low < 7 g/dL; transfusion often considered < 8 |
| Hematocrit (Hct) | M: 41–53% F: 36–46% | Roughly 3× Hgb; drops in hemorrhage and hemodilution |
| Platelets | 150,000 – 400,000 /μL | Thrombocytopenia < 150K; critical < 50K; spontaneous bleed risk < 20K |
| MCV | 80 – 100 fL | Low = microcytic (iron deficiency); high = macrocytic (B12/folate deficiency) |
Electrolytes
| Electrolyte | Normal Range | Critical Values / Notes |
|---|---|---|
| Sodium (Na⁺) | 136 – 145 mEq/L | Critical: < 120 or > 160 — seizure risk at extremes |
| Potassium (K⁺) | 3.5 – 5.0 mEq/L | Critical: < 3.0 or > 6.0 — cardiac dysrhythmia risk |
| Chloride (Cl⁻) | 98 – 106 mEq/L | Mirrors Na⁺; low in metabolic alkalosis; high in metabolic acidosis |
| Calcium (Ca²⁺) | 8.5 – 10.5 mg/dL | Hypocalcemia: Trousseau's and Chvostek's signs; tetany risk |
| Magnesium (Mg²⁺) | 1.5 – 2.5 mEq/L | Low Mg often accompanies low K⁺ and low Ca²⁺; torsades risk |
| Phosphorus (PO₄) | 2.5 – 4.5 mg/dL | Low in malnutrition/refeeding syndrome; high in renal failure |
BMP / CMP Basics
| Test | Normal Range | Notes |
|---|---|---|
| Glucose (fasting) | 70 – 100 mg/dL | Critical hypoglycemia < 40; hyperglycemic crisis > 600 (HHS) |
| BUN | 7 – 20 mg/dL | Elevated with dehydration, GI bleeding, or renal dysfunction |
| Creatinine | M: 0.7–1.3 mg/dL F: 0.6–1.1 mg/dL | Most specific renal function marker; rises in AKI and CKD |
| CO₂ (Bicarbonate) | 22 – 29 mEq/L | Venous CO₂ approximates serum HCO₃; reflects metabolic acid-base |
Renal Markers
| Test | Normal Range | Notes |
|---|---|---|
| eGFR | ≥ 60 mL/min/1.73m² | CKD staging: < 60 for > 3 months; dialysis threshold often < 15 |
| BUN:Creatinine Ratio | 10:1 – 20:1 | > 20:1 suggests prerenal azotemia; < 10:1 suggests intrinsic renal or liver disease |
| Uric Acid | M: 3.5–7.2 mg/dL F: 2.6–6.0 mg/dL | Elevated in gout, tumor lysis syndrome, renal failure |
Liver Function Tests (LFTs)
| Test | Normal Range | Notes |
|---|---|---|
| ALT | 7 – 56 IU/L | Most specific liver marker; elevated in hepatitis, fatty liver, medications |
| AST | 10 – 40 IU/L | Less specific (also in muscle, heart); elevated in liver disease, MI, muscle injury |
| Total Bilirubin | 0.1 – 1.2 mg/dL | Elevated in jaundice; direct (conjugated) vs indirect (unconjugated) helps identify cause |
| Alkaline Phosphatase (ALP) | 44 – 147 IU/L | Elevated in cholestasis, bile duct obstruction, bone disease |
| Albumin | 3.5 – 5.0 g/dL | Marker of liver synthetic function and nutritional status; affects drug binding |
Coagulation Studies
| Test | Normal Range | Notes |
|---|---|---|
| PT | 11 – 13.5 seconds | Tests extrinsic pathway; prolonged by warfarin, liver disease, Vit K deficiency |
| INR | 0.8 – 1.2 (therapeutic: 2.0–3.0 on warfarin) | Standardized PT ratio; used to monitor warfarin therapy |
| aPTT | 25 – 35 seconds (therapeutic heparin: 60–100 s) | Tests intrinsic pathway; used to monitor unfractionated heparin |
| D-Dimer | < 0.5 mg/L (lab-specific) | Elevated in DVT, PE, DIC; highly sensitive but not specific |
Practice Lab Value Recognition
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with ANA / NANDA Clinical Standards. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →