LabLiSign In
Panels/CBC
Lab Panel Guide

Complete Blood Count (CBC)

The CBC is one of the most common blood tests. It evaluates your overall health and detects a wide range of disorders including anemia, infection, and blood cancers.

Educational Information Only

This guide explains what CBC components measure. Normal ranges vary by lab, age, sex, and pregnancy status. Always discuss your results with a healthcare provider for proper interpretation.

What's Included in a CBC?

Red Blood Cells

  • • RBC count
  • • Hemoglobin
  • • Hematocrit
  • • MCV, MCH, MCHC
  • • RDW

White Blood Cells

  • • WBC count
  • • Differential (types)
  • • Neutrophils
  • • Lymphocytes
  • • Monocytes, Eos, Baso

Platelets

  • • Platelet count
  • • MPV (mean volume)

CBC Components Explained

White Blood Cell Count (WBC)

Leukocytes

4,500 - 11,000 cells/μL

Measures: Number of infection-fighting white blood cells

High: Infection, inflammation, leukemia, stress, steroid use
Low: Bone marrow problems, autoimmune disorders, chemotherapy, viral infections
MedlinePlus - WBC Count

Red Blood Cell Count (RBC)

Erythrocytes

4.5 - 5.5 million cells/μL (men), 4.0 - 5.0 (women)

Measures: Number of oxygen-carrying red blood cells

High: Dehydration, polycythemia, lung disease, living at high altitude
Low: Anemia, bleeding, bone marrow failure, kidney disease
MedlinePlus - RBC Count

Hemoglobin (Hgb)

Hb

14 - 18 g/dL (men), 12 - 16 g/dL (women)

Measures: Protein in red blood cells that carries oxygen

High: Dehydration, polycythemia, COPD, high altitude
Low: Anemia (iron, B12, or folate deficiency), bleeding, chronic disease
NHLBI - Hemoglobin|Full test guide

Hematocrit (Hct)

Packed Cell Volume (PCV)

40 - 54% (men), 36 - 48% (women)

Measures: Percentage of blood volume that is red blood cells

High: Dehydration, polycythemia vera, lung disease
Low: Anemia, overhydration, blood loss
Mayo Clinic - Hematocrit

Mean Corpuscular Volume (MCV)

Average RBC size

80 - 100 fL

Measures: Average size of red blood cells

High: B12 or folate deficiency, liver disease, hypothyroidism (macrocytic)
Low: Iron deficiency, thalassemia (microcytic)
Cleveland Clinic - MCV

Mean Corpuscular Hemoglobin (MCH)

Average Hgb per RBC

27 - 33 pg

Measures: Average amount of hemoglobin per red blood cell

High: Macrocytic anemia (B12/folate deficiency)
Low: Iron deficiency anemia, thalassemia
Healthline - MCH

Mean Corpuscular Hemoglobin Concentration (MCHC)

Hgb concentration in RBCs

32 - 36 g/dL

Measures: Average concentration of hemoglobin in red blood cells

High: Hereditary spherocytosis, severe dehydration
Low: Iron deficiency, thalassemia
Healthline - MCHC

Red Cell Distribution Width (RDW)

RBC size variation

11.5 - 14.5%

Measures: Variation in red blood cell size

High: Mixed anemias, early iron/B12 deficiency, recent transfusion
Low: Usually not clinically significant
Cleveland Clinic - RDW

Platelet Count

Thrombocytes

150,000 - 400,000 cells/μL

Measures: Number of clotting cells

High: Infection, inflammation, iron deficiency, cancer, spleen removal
Low: Bleeding disorders, bone marrow problems, autoimmune (ITP), medications
NHLBI - Platelet Count

Mean Platelet Volume (MPV)

Average platelet size

7.5 - 11.5 fL

Measures: Average size of platelets

High: Platelet destruction (body making new, larger platelets)
Low: Bone marrow suppression
Healthline - MPV

WBC Differential (Types of White Blood Cells)

A CBC with differential breaks down white blood cells by type. Each type fights different infections:

Neutrophils40-70%Fight bacterial infections
Lymphocytes20-40%Fight viral infections, produce antibodies
Monocytes2-8%Clean up dead cells, fight chronic infections
Eosinophils1-4%Fight parasites, involved in allergies
Basophils0.5-1%Allergic reactions, inflammation

Source: NCBI - White Blood Cells

When Is a CBC Ordered?

  • • Routine checkup — Part of annual physical
  • • Symptoms — Fatigue, weakness, bruising, fever, infection
  • • Monitoring — Chemotherapy, chronic conditions, medications
  • • Pre-surgery — Baseline before procedures
  • • Diagnosis — Anemia, infection, blood disorders

Mayo Clinic - Complete Blood Count

Track Your CBC Results Over Time

Upload your lab reports to see trends in your hemoglobin, WBC, platelets, and other blood markers.

Start Tracking Free

Related Resources

Anemia GuideHemoglobin TestLabs for FatigueCMP Panel
LabLi

Educational content only. Not medical advice. Always consult a healthcare provider.