Lab Values (Reference Ranges)

OVERVIEW

These are the official lab values that you will be given during the USMLE exam (and they have been taken directly from the practice software released by the test makers)

BLOOD, PLASMA, SERUM

Alanine aminotransferase (ALT): 8-20 U/L

Amylase, serum: 25-125 U/L

Aspartate aminotransferase (AST): 8-20 U/L

Bilirubin, serum (adult) Total// Direct: 0.1-1.0 mg/dL // 0.0-0.3 mg/dL

Calcium, serum (Ca²+): 8.4-10.2 mg/dL

Cholesterol, serum: Rec: <200 mg/dL

Cortisol, serum: 0800 h: 5-23 µg/dL // 1600 h: 2-15 µg/dL // 2000 h: ≤ 50% of 0800 h

Creatine kinase, serum: 

  • Male: 25-90 U/L
  • Female: 10-70 U/L

Creatinine, serum: 0.6-1.2 mg/dL

Electrolytes, serum: 

  • Sodium (Na+): 136-145 mEq/L
  • Chloride (Cl-):  95-105 mEq/L
  • Potassium (K+): 3.5-5.0 mEq/L
  • Bicarbonate (HCO3-): 22-28 mEq/L
  • Magnesium (Mg²+): 1.5-2.0 mEq/L

Estriol, total, serum (in pregnancy):

  • 24-28 wks: 30-170 ng/mL
  • 28-32 wks: 40-220 ng/mL
  • 32-36 wks: 60-280 ng/mL
  • 36-40 wks: 80-350 ng/mL

Ferritin, serum: 

  • Male:  15-200 ng/mL
  • Female: 12-150 ng/mL

Follicle stimulating hormone (FSH), serum/plasma: 

  • Male: 4-25 mlU/mL
  • Female (premenopausal): 4-30 mlU/mL
  • Female (midcycle peak): 10-90 mlU/mL
  • Female (postmenopause): 40-250 mlU/mL

Gases, arterial blood (room air): 

  • pH: 7.35-7.45
  • Pc02: 33-45 mmHg
  • P02: 75-105 mm Hg

Glucose, serum:

  • Fasting: 70-110 mg/dL
  • 2-h postprandial: < 120 mg/dL

Growth hormone- arginine stimulation:

  • Fasting: < 5 ng/mL
  • Provocative stimuli: > 7 ng/mL

Immunoglobulins, serum: 

  • IgA:  76-390 mg/dL
  • IgE:  0-380 IU/mL
  • IgG: 650-1500 mg/dL
  • IgM: 40-345

Iron: 50-170 µg/dL

Lactate dehydrogenase, serum: 45-90 U/L

Luteinizing hormone (LH), serum/plasma:

  • Male: 6-23 mlU/mL
  • Female (follicular phase): 5-30mlU/mL
  • Female (midcycle): 75-150 mlU/mL
  • Female (postmenopause): 30-200 mlU/mL

Osmolality, serum: 275-295 mOsmol/kg H2O

Parathyroid hormone, serum, N-terminal: 230-630 pg/mL

Phosphatase (alkaline), serum (p-NPP at 30°C): 20-70 U/L

Phosphorous (inorganic), serum: 3.0-4.5 mg/dL

Prolactin, serum (hPRL): <20 ng/mL

Proteins, serum: 

  • Total (recumbent): 6.0-7.8 g/dL
  • Albumin: 3.5-5.5 g/dL
  • Globulin: 2.3-3.5 g/dL

Thyroid-stimulating hormone (TSH), serum or plasma: 0.5-5.0 µU/mL

Thyroidal iodine (¹²³I) uptake: 8-30% of administered dose/24 h

Thyroxine (T4), serum: 5-12 µg/dL

Triglycerides, serum: 35-160 mg/dL

Triiodothyronine (T3), serum (RIA): 115-190 ng/dL

Triiodothyronine (T3), resin uptake: 25-35%

Urea nitrogen, serum: 7-18 mg/dL

Uric acid, serum: 3.0-8.2 mg/dL

HEMATOLOGIC

Bleeding time (template): 2-7 minutes

Erythrocyte count: 

  • Male: 4.3-5.9 million/mm³
  • Female: 3.5-5.5 million/mm³

Erythrocyte sedimentation rate/ESR (Westergren): 

  • Male: 0-15 mm/h
  • Female: 0-20 mm/h

Hematocrit: 

  • Male: 41-53%
  • Female: 36-46%

Hemoglobin A1C: ≤ 6%

Hemoglobin, blood: 

  • Male: 13.5-17.5 g/dL
  • Female: 12.0-16.0 g/dL

Hemoglobin, plasma1-4 mg/dL

Leukocyte count and differential: 

  • Leukocyte count: 4500-11,000/mm³
  • Segmented neutrophils: 54-62%
  • Bands: 3-5%
  • Eosinophils: 1-3%
  • Basophils: 0-0.75%
  • Lymphocytes: 25-33%
  • Monocytes: 3-7%

Mean corpuscular hemoglobin (MCH): 2.54-34.6 pg/cell

Mean corpuscular hemoglobin concentration (MCHC): 31%-36% Hb/cell

Mean corpuscular volume (MCV):  80-100µm³

Partial thromboplastin time/PTT (activated): 25-40 seconds

Platelet count: 150,000-400,000/mm³

Prothrombin time: 11-15 seconds

Reticulocyte count: 0.5%-1.5% of red cells

Thrombin time: <2 seconds deviation from control

Volume: 

  • Plasma (Male): 25-43 mL/kg
  • Plasma (Female): 28-45 mL/kg
  • Red cell (Male): 20-36 mL/kg
  • Red cell (Female): 19-31 mL/kg
CEREBROSPINAL

Cell count: 0-5/mm³

Chloride: 118-132 mEq/L

Gamma globulin: 3-12% total proteins

Glucose: 40-70 mg/dL

Pressure: 70-180 mm H2O

Proteins, total:  <40 mg/dL

URINE

Calcium: 100-300 mg/24 h

Chloride: varies with intake

Creatinine clearance: 

  • Male: 97-137 mL/min
  • Female: 88-128 mL/min

Estriol, total (in pregnancy): 

  • 30 wks: 6-18 mg/24 h
  • 35 wks: 9-28 mg/24 h
  • 40 wks: 13-42 mg/24 h

17-Hydroxycorticosteroids: 

  • Male: 3.0-10.0 mg/24 h
  • Female: 2.0-8.0 mg/24 h

17-Ketosteroids, total:

  • Male: 8-20 mg/24 h
  • Female: 6-15 mg/24 h

Osmolality: 50-1400 mOsmol/kg H2O

Oxalate: 8-40 µg/mL

Potassium: varies with diet

Proteins, total:  <150 mg/24 h

Sodium: varies with diet

Uric acid: varies with diet

SWEAT

Chloride: 0-35 mmol/L

BMI

Adult: 19-25 kg/m²

 

Page Updated: 01.22.2016