Lab Values

What Labs Do I Have to Know for the Exam?

• ABGs (pH, PO2, SaO2, HCO3)

• BUN & Creatinine

• Cholesterol (total)

• Glucose & HgbA1C

• Potassium & Sodium

• WBC

• Hematocrit & Hemoglobin

• Platelets

• PTT & aPTT and INR & PT

Laboratory values and units vary among sources and laboratories. Since there is no specified, accepted lab resource for the NCLEX, we recommend you use the lab values you learned in school. 

Labs marked with asterisks are those that students are responsible for knowing for the NCLEX, as indicated on the NCSBN Educator Test Blueprint:

Complete Blood Count (CBC)

RBC
  Male: 4.7-6.6 million
  Female: 4.2-5.4 million
WBC * 5,000-10,000 cells/ml
Critical WBC * 2,000 or >40,000/ml
Neutrophils 55-70%
Lymphocytes 20-40%
Monocytes 2-8%
Eosinophils 1-4%
Basophils 0.5-1%
Hemoglobin *
  Male: 14-18 g/dl
  Female: 12-16 g/dl
  Pregnant Female: > 11 g/dl
Hematocrit *
  Male: 42-52%
  Female: 37-47%
  Pregnant Female: > 33%
Platelets *
   Adults > 150,000-400,000
   Critical Plts * > <50,000 or > 1 million

Comprehensive Metabolic Panel (CMP)

Sodium (Na) * 136-145 mEq/L
Critical Sodium * <120 or > 160 mEq/L
Potassium (K) * 3.5-5.0 mEq/L
Critical Potassium * <3 or >6.1mEq/L
Chloride 98-106 mEq/L
Calcium 9-10.5 mg/dl
Magnesium 1.3-2.1 mEq/L
Phosphorus 3-4.5 mg/dl
Glucose *
  Fasting: 70-110 mg/dl
  Random: ≤ 200 mg/dl
  Critical Glucose *
      Male: <50 and >400 mg/dl
      Female: <40 and >400 mg/dl
BUN * 10-20 mg/dl
Critical BUN * >100 mg/dl
Creatinine *
  Male: 0.6-1.2 mg/dl
  Female: 0.5-1.1 mg/dl
  Critical Creatinine * >4 mg/dl
Total Protein 6.4-8.3 g/dl
Albumin 3.5-5.0 g/dl
Bilirubin 0.3-1 mg/dl
Alkaline Phosphatase 30-120 units/L
ALT 4-36 international units/L
AST 0-35 units/L

Arterial Blood Gas (ABG)

pH * 7.35-7.45
Critical pH * <7.25 or >7.6
pCO* 35-45 mmHg
Critical pCO* < 20 or >60 mmHg
pO* 80-100 mmHg
Critical pO* (arterial) <40 mmHg
HCO* 21-28 mEq/L
Critical HCO* <10 or >40 mEq/L
SaO* 95%-100%
Critical SaO* 75% or lower

Coagulation

PT * 11-12.5 seconds
With anticoagulant therapy
                          > 1.5-2 X control value
INR *
    0.8-1.1
    2-3 (A-fib anticoagulant therapy)
    3-4 (Prosthetic valve prophylaxis)
aPTT * 30-40 seconds
With anticoagulant therapy
                   1.5-2.5 times control value
Critical aPTT * > 70 seconds
D-Dimer negative

Cardiac

Troponin-I <0.03 ng/ml
BNP <100 pg/ml
CK (Creatine Kinase)
  Male: 55-170 U/L
  Female: 30-135 U/L
C-reactive protein
  <1.0 mg/dl (low cardiac risk)
  >3.0 mg/dl (high cardiac risk)
Lactate dehydrogenase (LDH) 100-190 U/L

Urinalysis

Glucose:

  Random specimen: should not be detected 

  24-hr specimen: 50-300 mg/24 hr 

Protein:

  0-8 mg/dL 

  50-80 mg/24 hr (at rest) 

  In random specimen, more than trace indicates proteinurea.

pH:

  4.6-8.0 

  6 is average 

Ketones:

  Should not be detected.

  Low pH may cause a color change resulting in a false positive.

Specific gravity:
  1.005 - 1.030
Blood:
  Blood may be present during menstruation or with external skin damage, neither of which is indicative of  hematuria.
Bilirubin:
  Should be negative, but OTC selenium and Pyridium can cause false positives
All others:
  Should be negative

Other

Triglycerides *
  Male: 40-160 mg/dl
  Female: 35-135 mg/dl
Total cholesterol * <200 mg/dl
HDL *
  Male: >45 mg/dl
(> 60 = low risk for heart disease)
  Female: >60 mg/dl
(> 70 = low risk for heart disease)
LDL *
  Male and Female: <100 mg/dl
Lactate
  0.6-2.2 mmol/L or
  5-20 mg/dl (venous blood)
Hgb A1C *
  Non-diabetic 4-5.7%
  Good diabetes control <7%
  Poor diabetes control >9%
TSH 0.3-5 μ/L
Free T4 0.8-2.8 ng/dl
Total T4 4.5-12 ng/dl
Critical Total T4
  <2 mcg/dL if myxedema coma possible
  >20 mcg/dL if thyroid storm possible
Free T3 1.2-3.4 nmol/ml
Uric Acid
  Male: 4.0-8.5 mg/dl
  Female: 2.7-7.3 mg/dl
Erythrocyte sedimentation rate (Westergen Method)
  Male: up to 15 mm/hour
  Female: up to 20 mm/hour
Amylase
  60-120 Somogyi units/dL
  30-220 units/L (SI units)
Lipase 0-160 units/L
Myoglobin <90 mcg/L
Ammonia 10-80mcg/dl
Iron
  Male: 80-180 mcg/dl
  Female: 60-160 mcg/dl

Updated 2018

NCLEX Mastery provides reference ranges from Mosby's Manual of Laboratory and Diagnostic Tests (Pagana and Pagana, 2015).