Interpretation of RBC Count 5.84 × 10⁶/µL
Normal Range Assessment
An RBC count of 5.84 × 10⁶/µL is within the normal range for adult males and at the upper limit of normal for adult females, and typically does not require further evaluation in an asymptomatic patient. 1
Context-Dependent Interpretation
The clinical significance of this RBC count depends on several key factors:
Sex-specific reference ranges: Normal RBC counts for adult males are approximately 4.5–5.9 × 10⁶/µL, while for adult females they are 4.1–5.1 × 10⁶/µL. 1
Hemoglobin and hematocrit correlation: The RBC count must be interpreted alongside hemoglobin and hematocrit values, as these parameters are highly correlated and provide complementary information about oxygen-carrying capacity. 2, 3
Mean corpuscular volume (MCV): An elevated RBC count with normal or low MCV suggests a different clinical picture than one with elevated MCV. 4, 5
When Further Evaluation Is Indicated
Further workup should be considered if:
Symptoms of polycythemia are present, including headache, dizziness, pruritus after bathing, erythromelalgia, or thrombotic events. 2
Hemoglobin is elevated above normal ranges (>16.5 g/dL in men or >16.0 g/dL in women), suggesting true polycythemia rather than isolated RBC elevation. 2
Cardiovascular risk factors are present, as elevated RBC count has been weakly associated with increased cardiovascular disease incidence in some populations. 3
Myeloproliferative features are suspected, such as splenomegaly, elevated white blood cell count, or thrombocytosis. 2
Recommended Diagnostic Approach
If clinical concern exists based on the above factors:
Complete blood count with differential: Evaluate hemoglobin, hematocrit, MCV, MCH, MCHC, and white blood cell and platelet counts to assess for myeloproliferative disorders. 2, 5
Peripheral blood smear: Examine RBC morphology for abnormalities that may indicate underlying hematologic conditions. 5
JAK2V617F mutation testing: Consider if polycythemia vera is suspected based on elevated hemoglobin/hematocrit with elevated RBC count. 2
Erythropoietin level: Measure to distinguish primary (low EPO) from secondary (high EPO) polycythemia if hemoglobin is also elevated. 2
Common Pitfalls to Avoid
Do not assume pathology based solely on an RBC count at the upper limit of normal without evaluating hemoglobin, hematocrit, and clinical context. 1, 3
Do not overlook sex-specific reference ranges: A value normal for males may be elevated for females. 1
Do not ignore instrument-specific variations: Modern automated hematology analyzers may have slightly different reference ranges, and results should be interpreted using laboratory-specific normal values. 4, 6
Do not pursue extensive workup in asymptomatic patients with isolated borderline RBC elevation and normal hemoglobin/hematocrit. 3