RBC Indices: MCV, MCH, and MCHC

Vocabulary flashcards covering the key Red Blood Cell (RBC) indices—MCV, MCH, and MCHC—including definitions, formulas, units, normal adult reference ranges, patterns of anemia, causes, and real lab examples.

MCV (Mean Corpuscular Volume)

The average size (volume) of one RBC, measured in $fL$ (femtoliters) with an adult normal range of $80-100\,fL$, best used for classifying anemia as microcytic, normocytic, or macrocytic.

MCV Formula

\text{MCV} = \frac{\text{Hct (\%)} \times 10}{\text{RBC (million/\mu L)}}

MCH (Mean Corpuscular Hemoglobin)

The average amount of hemoglobin per RBC, measured in $pg$ (picograms) with an adult normal range of $27-33\,pg$, used to support diagnosis and assess severity.

MCH Formula

\text{MCH} = \frac{\text{Hb (g/dL)} \times 10}{\text{RBC (million/\mu L)}}

MCHC (Mean Corpuscular Hemoglobin Concentration)

The concentration of hemoglobin inside RBCs, measured in $g/dL$ (grams per deciliter) with an adult normal range of $32-36\,g/dL$, best used for determining chromia (hypochromia or normochromia).

MCHC Formula

$$\text{MCHC} = \frac{\text{Hb (g/dL)} \times 100}{\text{Hct (\%)}}$$

Microcytic, Hypochromic Anemia Pattern

An RBC index pattern defined by low MCV, low MCH, and low MCHC, commonly caused by iron deficiency anemia, thalassemia, or anemia of chronic disease.

Normocytic, Normochromic Pattern

An RBC index pattern where MCV, MCH, and MCHC are within normal range, commonly caused by acute blood loss, hemolytic anemia, anemia of chronic disease, kidney disease, or bone marrow disorders.

Macrocytic, Normochromic Anemia Pattern

An RBC index pattern defined by high MCV, high MCH, and normal or low MCHC, commonly caused by Vitamin B12 deficiency, folate deficiency, liver disease, alcohol use, hypothyroidism, certain drugs, or reticulocytosis.

Increased MCHC Pattern

An RBC index pattern defined by normal or low MCV, normal or low MCH, and high MCHC (suggesting spherocytes), commonly caused by hereditary spherocytosis, autoimmune hemolytic anemia, severe dehydration (artifact), or cold agglutinins (artifact).

Iron Deficiency Anemia Lab Example

A representative laboratory result profile showing MCV $72\,fL$, MCH $23\,pg$, and MCHC $29\,g/dL$.

Normal RBC Indices Lab Example

A representative laboratory result profile showing MCV $88\,fL$, MCH $30\,pg$, and MCHC $34\,g/dL$.

Hereditary Spherocytosis Lab Example

A representative laboratory result profile showing MCV $72\,fL$, MCH $25\,pg$, and MCHC $37\,g/dL$.

Red Blood Cell Index Evaluation Approach

The clinical standard of combining MCV (size), MCH (amount), and MCHC (concentration) together with RDW (variation) and peripheral smear alongside clinical history to achieve an accurate anemia diagnosis.