Complete Blood Count (CBC) Reference Chart

Enhanced with Clinical Interpretations and Diagnostic Context

Component Age Group Male Range Female Range Clinical Notes
Hemoglobin (HGB)
g/dL		 Adult 13.5 - 18.0 12.0 - 16.0
Low HGB (Anemia): Blood loss, nutritional deficiency, chronic disease
High HGB (Erythrocytosis): Dehydration, smoking, high altitude, polycythemia vera
Pregnancy: Lower limit typically 10 g/dL due to plasma expansion
12-17 years 13.0 - 16.0 12.0 - 16.0
6-11 years 11.5 - 15.5 11.5 - 15.5
Hematocrit (HCT)
%		 Adult 41.0 - 53.0 36.0 - 47.0
Calculation: HCT = RBC × MCV/10
Mirroring HGB: Reduced in anemia, increased in erythrocytosis
Plasma Volume Effects: Affected by hydration status
12-17 years 37.0 - 49.0 36.0 - 46.0
6-11 years 35.0 - 45.0 35.0 - 45.0
Mean Corpuscular Volume (MCV)
fL		 Adult 80 - 95 80 - 95
Microcytic (<80): Iron deficiency, thalassemia, lead poisoning
Normocytic (80-100): Acute blood loss, chronic disease
Macrocytic (>100): B12/folate deficiency, alcohol use, liver disease
White Blood Cell Count (WBC)
10³/µL		 Adult 4.1 - 11.0 4.1 - 11.0
Leukopenia (<4.5): Bone marrow failure, viral infections, medications
Leukocytosis (>11.0): Bacterial infections, inflammation, malignancy
Differential Required: Assess which cell types are affected
Neutrophils
%		 Adult 35.0 - 75.0 35.0 - 75.0
Neutrophilia: Bacterial infections, stress, medications, malignancy
Neutropenia: Viral infections, chemotherapy, autoimmune disease
Critical Threshold: <1500/µL increases infection risk significantly
Psychiatric Note: ANC monitoring essential for clozapine therapy. See Clozapine Monitoring tab for detailed thresholds.
Absolute Neutrophil Count (ANC)
cells/µL		 Adult 1,800 - 7,700 1,800 - 7,700
Formula: ANC = WBC × (% segmented neutrophils + % band neutrophils)
Clinical Significance: Primary parameter for infection risk assessment
BEN (Benign Ethnic Neutropenia): Lower baseline ANC (~1000-1500/µL) in ~25-50% of individuals of African descent
Clozapine Thresholds:
• General population: ≥1500/µL required to initiate
• BEN patients: ≥1000/µL sufficient for initiation
Lymphocytes
%		 Adult 16.0 - 52.0 16.0 - 52.0
Lymphocytosis: Viral infections, lymphoproliferative disorders
Lymphopenia: Immunodeficiency, autoimmune disease, medications
Age Variation: Higher percentages normal in children
Platelet Count (PLT)
10³/µL		 Adult 150 - 450 150 - 450
Thrombocytopenia (<150): Bleeding risk below 50k, spontaneous bleeding below 20k
Thrombocytosis (>450): Rarely symptomatic unless >1 million
EDTA Effect: Clumping may cause falsely low counts

Anemia Severity Grading (WHO Guidelines)

Population Mild Anemia (g/dL) Moderate Anemia (g/dL) Severe Anemia (g/dL)
Men 11.0 - 12.9 8.0 - 10.9 < 8.0
Non-pregnant Women 11.0 - 11.9 8.0 - 10.9 < 8.0
Pregnant Women 10.0 - 10.9 7.0 - 9.9 < 7.0

Anemia Classification by MCV and RDW

Microcytic (<80 µm³)

Normal RDW (11.5-15%):
  • Thalassemia
  • Anemia of chronic disease
  • Lead poisoning
Elevated RDW (>15%):
  • Iron deficiency
  • Red cell fragmentation
  • Sideroblastic anemia

Normocytic (80-100 µm³)

Normal RDW:
  • Anemia of chronic disease
  • Acute hemorrhage
  • Hereditary spherocytosis
Elevated RDW:
  • Early iron or folate deficiency
  • Mixed deficiency
  • Sickle cell anemia

Macrocytic (>100 µm³)

Normal RDW:
  • Chronic liver disease
  • Hypothyroidism
  • Alcohol use
Elevated RDW:
  • Folate deficiency
  • Vitamin B12 deficiency
  • Myelodysplastic syndrome

Red Blood Cell Indices - Clinical Significance

Mean Corpuscular Hemoglobin (MCH): Normal 27-32 pg/cell. Correlates with MCV and helps evaluate hemoglobin content per cell.

Mean Corpuscular Hemoglobin Concentration (MCHC): Normal 32-36%. Measures hemoglobin density within cells.

Clinical Pearl: MCHC is regulated and normally limited to ~34% Hb/cell. Values >36% often indicate laboratory artifact.

White Blood Cell Differential - Clinical Context

Neutrophils (1800-7700 cells/µL):

  • Increased: Bacterial infections, stress, corticosteroids, smoking
  • Decreased: Viral infections, chemotherapy, autoimmune disease

Lymphocytes (1200-4800 cells/µL):

  • Increased: Viral infections, lymphoproliferative disease
  • Decreased: Immunodeficiency, corticosteroids, chronic illness

Eosinophils (0-500 cells/µL):

  • Increased: Allergies, parasitic infections, drug reactions
  • Decreased: Acute stress, corticosteroids

Platelet Function and Clinical Thresholds

Bleeding Risk Assessment:
• >50,000/µL: Usually adequate for most procedures
• 20,000-50,000/µL: Minor bleeding risk
• <20,000/µL: Spontaneous bleeding risk
• <10,000/µL: High risk of spontaneous cerebral bleeding

🧠 Psychiatric Relevance: CBC in Clozapine Monitoring

Clozapine, an atypical antipsychotic for treatment-resistant schizophrenia, carries a risk of life-threatening neutropenia. Regular ANC monitoring via CBC with differential remains essential for safe clozapine prescribing. This tool supports psychiatric providers in real-time interpretation of ANC trends and clozapine prescribing safety.

ANC Calculator

Formula: ANC = WBC × (% Segmented Neutrophils + % Band Neutrophils)




Clozapine ANC Thresholds & Actions

ANC Category General Population BEN Population Recommended Action
Normal ≥1500/µL ≥1000/µL Continue clozapine, routine monitoring
Mild Neutropenia 1000-1499/µL 500-999/µL Continue clozapine, increase monitoring frequency
Moderate Neutropenia 500-999/µL — Interrupt clozapine, daily ANC monitoring
Severe Neutropenia <500/µL <500/µL 🚨 DISCONTINUE clozapine immediately, hematology consult
BEN (Benign Ethnic Neutropenia): Affects ~25-50% of individuals of African descent. Lower baseline ANC is constitutional and not associated with increased infection risk.

CBC Monitoring Frequency by Treatment Duration

Phase 1: Initial Treatment

Duration: Weeks 1-26 (6 months)

Frequency: Weekly CBC with differential

Rationale: Highest risk period for neutropenia

Phase 2: Continuation

Duration: Weeks 27-52 (6-12 months)

Frequency: Biweekly CBC with differential

Rationale: Intermediate risk period

Phase 3: Maintenance

Duration: >52 weeks (>12 months)

Frequency: Monthly CBC with differential

Rationale: Lower risk after first year

🚨 Critical Clinical Flags

  • ANC <500/µL: Requires immediate clozapine discontinuation unless risks of interruption outweigh benefits. Consider immediate hematology consultation.
  • Declining ANC trend: Even within normal range, a consistent downward trend warrants closer monitoring.
  • Concomitant medications: Be aware of other drugs that may cause neutropenia (e.g., carbamazepine, sulfonamides).
  • Patient education: Patients should report signs of infection immediately (fever, sore throat, flu-like symptoms).

⚠️ Common Sources of Spurious CBC Results

Understanding artifacts prevents misdiagnosis and unnecessary interventions.

Component Spurious Increase Spurious Decrease
Hemoglobin Lipemia, hyperbilirubinemia, paraproteinemia, hyperleukocytosis Sample diluted with IV fluid infusion
Hematocrit Hyperglycemia, hyperleukocytosis Red cell agglutination, sample diluted with IV fluid
MCV Red cell agglutination, hyperglycemia, hypernatremia, hyperleukocytosis —
MCHC Lipemia, hemolysis, red cell agglutination Hyperglycemia, hyperbilirubinemia
WBC Reticulocytosis, platelet clumping, fibrin clumps WBC clumping
Platelet Count Bacteremia, fungemia, malaria, red cell fragments Platelet clumping (EDTA-induced)
Important: When spurious results are suspected, peripheral blood smear examination is essential for accurate interpretation. Consider collecting samples in citrate or oxalate tubes if EDTA-induced platelet clumping is suspected.

Reference Information

Source: El Brihi, J., & Pathak, S. (2024). Normal and abnormal complete blood count with differential. In StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK604207/

Note: Reference intervals are laboratory-specific. Always refer to your local laboratory's established ranges for clinical decision-making. This chart provides commonly used reference intervals and should not replace clinical judgment or laboratory guidelines.

Disclaimer:

The information provided in this Complete Blood Count (CBC) Reference Tool is intended solely for educational and informational purposes. It does not constitute medical advice, diagnosis, or treatment, nor does it establish a provider-patient relationship. While efforts have been made to ensure the accuracy and clinical relevance of the content, PsychConcierge PLLC and PsychConcierge.com make no warranties, express or implied, regarding the completeness, reliability, or applicability of the information presented. Users are strongly encouraged to consult their licensed healthcare provider or local clinical laboratory for interpretation of laboratory values and individualized medical decisions. Reference ranges may vary by lab and patient population. PsychConcierge PLLC assumes no responsibility for any outcomes arising from reliance on this tool.