Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
WBR labs
Introduction
| WikiDoc Board Review |
|---|
| The Project |
| The Team |
| Guidelines |
| Question List |
| Quality Checklist |
| Medical Illustrations |
| Question Template |
| High Yield! |
| Normal Labs |
| Mnemonics |
| Test Taking Tips |
| Resources |
USMLE Laboratory Values
Find a list of normal ranges of laboratory values commonly tested on USMLE examinations.
Serum
| General Chemistry | Reference Range | Reference Intervals |
|---|---|---|
| Electrolytes | ||
| Sodium (Na+) | 136–146 mEq/L | 136–146 mmol/L |
| Potassium (K+) | 3.5–5.0 mEq/L | 3.5–5.0 mmol/L |
| Chloride (Cl–) | 95–105 mEq/L | 95–105 mmol/L |
| Bicarbonate (HCO3–) | 22–28 mEq/L | 22–28 mmol/ |
| Urea nitrogen | 7–18 mg/dL | 2.5–6.4 mmol/L |
| Creatinine | 0.6–1.2 mg/dL | 53–106 μmol/L |
| Glucose Fasting:
Random, non-fasting: |
70–100 mg/dL
<140 mg/dL |
3.8–5.6 mmol/L
<7.77 mmol/L |
| Calcium | 8.4–10.2 mg/dL | 2.1–2.6 mmol/L |
| Magnesium (Mg2+) | 1.5–2.0 mg/dL | 0.75–1.0 mmol/L |
| Phosphorus (inorganic) | 3.0–4.5 mg/dL | 1.0–1.5 mmol |
| Hepatic | Reference Range | Reference Intervals |
|---|---|---|
| Alanine aminotransferase (ALT) | 10–40 U/L | 10–40 U/L |
| Aspartate aminotransferase (AST) | 12–38 U/L | 12–38 U/L |
| Alkaline phosphatase | 25–100 U/L | 25–100 U/L |
| Amylase | 25–125 U/L | 25–125 U/L |
| Bilirubin, Total // Direct | 0.1–1.0 mg/dL // 0.0–0.3 mg/dL | 2–17 μmol/L // 0–5 μmol/L |
| Proteins, total | 6.0–7.8 g/dL | 60–78 g/L |
| Albumin | 3.5–5.5 g/dL | 35–55 g/L |
| Globulin | 2.3–3.5 g/dL | 23–35 g/L |
| Lipids | Reference Range | Reference Intervals |
|---|---|---|
| Cholesterol | ||
| Total Normal: | <200 mg/dL | <5.2 mmol/L |
| High: | >240 mg/dL | >6.2 mmol/L |
| HDL | 40–60 mg/dL | 1.0–1.6 mmol/L |
| LDL | <160 mg/dL | <4.2 mmol/L |
| Triglycerides | ||
| Normal | <150 mg/dL | <1.70 mmol/L |
| Borderline | 151–199 mg/dL | 1.71–2.25 mmol/L |
| Iron | Reference Range | Reference Intervals |
|---|---|---|
| Ferritin | ||
| Male: | 20–250 ng/mL | 20–250 μg/L |
| Female: | 10–120 ng/mL | 10–120 μg/L |
| Iron | ||
| Male: | 65–175 μg/dL | 11.6–31.3 μmol/L |
| Female: | 50–170 μg/dL | 9.0–30.4 μmol/L |
| Total iron-binding capacity | 250–400 μg/dL | 44.8–71.6 μmol/L |
| Transferrin | 200–360 mg/dL | 2.0–3.6 g/L |
| Endocrine | Reference Range | Reference Intervals |
|---|---|---|
| Hemoglobin A1c | ≤6% | ≤42 mmol/mo |
| Follicle-stimulating hormone | ||
| Male: | 4–25 mIU/mL | 4–25 IU/L |
| Female:
premenopause |
4–30 mIU/mL | 4–30 IU/L |
| midcycle peak | 10–90 mIU/mL | 10–90 IU/L |
| postmenopause | 40–250 mIU/mL | 40–250 IU/L |
| Luteinizing hormone | ||
| Male: | 6–23 mIU/mL | 6–23 IU/L |
| Female:
follicular phase |
5–30 mIU/mL | 5–30 IU/L |
| midcycle | 75–150 mIU/mL | 75–150 IU/L |
| postmenopause | 30–200 mIU/mL | 30–200 IU/L |
| Growth hormone
Arginine stimulation Fasting: |
<5 ng/mL | <5 μg/L |
| Provocative stimuli: | >7 ng/mL | >7 μg/L |
| Prolactin (hPRL)
Male: |
<17 ng/mL | <17 μg/L |
| Female: | <25 ng/mL | <25 μg/L |
| Cortisol
Female |
<25 ng/mL | <25 μg/L |
| 0800 h: | 5–23 μg/dL | 138–635 nmol/L |
| 1600 h: | 3–15 μg/dL | 82–413 nmol/L |
| 2000 h: | 2000 h: <50% of 0800 h | Fraction of 0800 h: <0.50 |
| TSH | 0.4–4.0 μU/mL | 0.4–4.0 mIU/L |
| Triiodothyronine (T3) (RIA) | 100–200 ng/dL | 1.5–3.1 nmol/L |
| Triiodothyronine (T3) resin uptake | 25%–35% | 0.25–0.35 |
| Thyroxine (T4) | 5–12 μg/dL | 64–155 nmol/L |
| Free T4 | 0.9–1.7 ng/dL | 12.0–21.9 pmol/L |
| Thyroidal iodine (123I) uptake | 8%–30% of administered dose/ | 24 h 0.08–0.30/24 h |
| PTH intact | 10–60 pg/mL | 10–60 ng/L |
| 17-Hydroxycorticosteroids
Male: |
3.0–10.0 mg/24 h | 8.2–27.6 μmol/24 h |
| Female: | 2.0–8.0 mg/24 h | 5.5–22.0 μmol/24 h |
| 17-Ketosteroids, total
Male: |
8–20 mg/24 h | 28–70 μmol/24 h |
| Female: | 6–15 mg/24 h | 21–52 μmol/24 |
| Inmunoglobulins | Reference Range | Reference Intervals |
|---|---|---|
| IgA | 76–390 mg/dL | 0.76–3.90 g/L |
| IgE | 0–380 IU/mL | 0–380 kIU/L |
| IgG | 650–1500 mg/dL | 6.5–15.0 g/L |
| IgM | 50–300 mg/dL | 0.5–3.0 g/L |
| Reference Range | Reference Intervals | |
|---|---|---|
| Creatinine clearance
Male: |
97–137 mL/min | 97–137 mL/min |
| Female: | 88–128 mL/min | 88–128 mL/min |
| Creatine kinase
Male: |
25–90 U/L | 25–90 U/L |
| Female: | 10–70 U/L | 10–70 U/L |
| Lactate dehydrogenase | 45–200 U/L | 45–200 U/L |
| Osmolality | 275–295 mOsmol/kg H2O | 275–295 mOsmol/kg H2O |
| Uric acid | 3.0–8.2 mg/dL | 0.18–0.48 mmol/L |
| Urine | Reference Range | Reference Intervals |
|---|---|---|
| Calcium | 100–300 mg/24 h | 2.5–7.5 mmol/24 h |
| Osmolality | 50–1200 mOsmol/kg H2O | 50–1200 mOsmol/kg H2O |
| Oxalate | 8–40 μg/mL | 90–445 μmol/L |
| Proteins, total | <150 mg/24 h | <0.15 g/24 h |
| Reference Range | Reference Intervals | |
|---|---|---|
| PO2 | 75–105 mm Hg | 10.0–14.0 kPa |
| PCO2 | 33–45 mm Hg | 4.4–5.9 kPa |
| pH | 7.35–7.45 [H+] | 36–44 nmol/L |
| Cerebrospinal Fluid (CSF) | Reference Range | Reference Intervals |
|---|---|---|
| Cell count | 0–5/mm3 | 0–5 × 106/L |
| Chloride | 118–132 mEq/L | 118–132 mmol/L |
| Gamma globulin | 3%–12% total proteins | 0.03–0.12 |
| Glucose | 40–70 mg/dL | 2.2–3.9 mmol/L |
| Pressure | 70–180 mm H2O | 70–180 mm H2O |
| Proteins, total | <40 mg/dL | <0.40 g/L |
| Complete Blood Count: | Reference Range | Reference Intervals |
|---|---|---|
| Hematocrit
Male: |
41%–53% | 0.41–0.53 |
| Female: | 36%–46% | 0.36–0.46 |
| Hemoglobin, blood
Male: |
13.5–17.5 g/dL | 135–175 g/L |
| Female: | 12.0–16.0 g/dL | 120–160 g/L |
| Mean corpuscular hemoglobin (MCH) | 25–35 pg/cell | 0.39–0.54 fmol/cell |
| Mean corpuscular hemoglobin conc. (MCHC) | 31%–36% Hb/cell | 4.8–5.6 mmol Hb/L |
| Mean corpuscular volume (MCV) | 80–100 μm3 | 80–100 fL |
| Volume
Plasma Male: |
25–43 mL/kg | 0.025–0.043 L/kg |
| Female: | 28–45 mL/kg | 0.028–0.045 L/kg |
| Red cell
Male: |
20–36 mL/kg | 0.020–0.036 L/kg |
| Female: | 19–31 mL/kg | 0.019–0.031 L/kg |
| Leukocyte count (WBC) | 4500–11,000/mm3 | 4.5–11.0 × 109/L |
| Neutrophils, segmented | 54%–62% | 0.54–0.62 |
| Neutrophils, bands | 3%–5% | 0.03–0.05 |
| Lymphocytes | 25%–33% | 0.25–0.33 |
| Monocytes | 3%–7% | 0.03–0.07 |
| Eosinophils | 1%–3% | 0.01–0.03 |
| Basophils | 0%–0.75% | 0.00–0.0075 |
| Platelet count | 150,000–400,000/mm3 | 150–400 × 109/L |
| Coagulation | Reference Range | Reference Intervals |
|---|---|---|
| Partial thromboplastin time (PTT) (activated) | 25–40 seconds | 25–40 seconds |
| Prothrombin time (PT) | 11–15 seconds | 11–15 seconds |
| D-Dimer | ≤250 ng/mL | ≤1.4 nmol/L |
| Reference Range | Reference Intervals | |
|---|---|---|
| Reticulocyte count | 0.5%–1.5% | 0.005–0.015 |
| Erythrocyte count
Male: |
4.3–5.9 million/mm3 | 4.3–5.9 × 1012/L |
| Female: | 3.5–5.5 million/mm3 | 3.5–5.5 × 1012/L |
| Erythrocyte sedimentation rate (Westergren)
Male: |
0–15 mm/h | 0–15 mm/h |
| Female: | 0–20 mm/h | 0–20 mm/h |
| CD4+ T-lymphocyte count | ≥500/mm3 | ≥0.5 × 109/L |
| Troponin I | ≤0.04 ng/mL | ≤0.04 μg/L |