In an adult male with hemoglobin consistently 15.8–17 g/dL, is this considered polycythemia requiring further evaluation?

Hemoglobin 15.8–17 g/dL in Adult Males: Normal Range, No Polycythemia Evaluation Required

A hemoglobin level of 15.8–17 g/dL in an adult male falls within the normal physiological range and does not meet diagnostic criteria for polycythemia vera or warrant further hematologic evaluation. 1, 2

Normal Hemoglobin Reference Ranges

• Adult males have a mean hemoglobin of 15.5 ± 2.0 g/dL, with the normal range extending up to approximately 17.0 g/dL at the 97.5th percentile. 1, 2
• The World Health Organization defines anemia as hemoglobin <13.0 g/dL in men, establishing the lower boundary of normal, but does not define polycythemia at these levels. 3, 4
• Your patient's hemoglobin values (15.8–17 g/dL) represent the mid-to-upper normal range for healthy adult males. 1, 2

Diagnostic Thresholds for Polycythemia Vera

Polycythemia vera requires hemoglobin ≥18.5 g/dL in men or ≥16.5 g/dL in women according to WHO criteria—significantly higher than your patient's values. 1, 2

WHO Major Diagnostic Criteria:

• Elevated hemoglobin >18.5 g/dL (men) or >16.5 g/dL (women), OR hematocrit >52% (men) or >49% (women). 1, 2
• Presence of JAK2 mutation (V617F or exon 12). 1, 2

When to Consider Further Evaluation:

• A sustained increase of ≥2 g/dL from the patient's previous baseline hemoglobin warrants investigation, even if absolute values remain below 18.5 g/dL. 2
• Clinical features suggesting myeloproliferative neoplasm (splenomegaly, thrombocytosis, leukocytosis, unusual thrombosis, aquagenic pruritus). 1, 2
• Hemoglobin >18.0 g/dL or hematocrit >52% in males should prompt diagnostic evaluation. 1

Clinical Context and Physiological Variations

Several physiological factors can elevate hemoglobin within the normal range without indicating pathology:

• Smoking increases hemoglobin by 0.3–1.0 g/dL due to chronic carbon monoxide exposure and tissue hypoxia. 1, 2
• Altitude adjusts expected hemoglobin values by approximately 0.9 g/dL per 1,000 meters elevation. 1, 2
• Testosterone naturally elevates hemoglobin in males, with gender differences emerging at puberty. 1
• Dehydration or plasma volume contraction can transiently elevate hemoglobin concentration. 1

Common Pitfalls to Avoid

• Do not order JAK2 mutation testing, bone marrow biopsy, or erythropoietin levels for hemoglobin values in the normal range (15.8–17 g/dL). 1, 2
• Do not perform therapeutic phlebotomy for hemoglobin <20 g/dL and hematocrit <65%, as this causes iron depletion and paradoxically increases stroke risk. 1
• Hemoglobin is more reliable than hematocrit for assessment, as hematocrit can falsely increase by 2–4% with prolonged sample storage or hyperglycemia. 1

When Reassessment Is Appropriate

Annual hemoglobin monitoring is reasonable for patients with chronic kidney disease or other conditions predisposing to hematologic changes, but is not required for healthy males with normal values. 3

• If hemoglobin rises above 18.0 g/dL or shows a sustained increase of ≥2 g/dL from baseline, initiate evaluation with complete blood count, JAK2 mutation testing, and assessment for secondary causes. 1, 2
• Evaluate for secondary causes first (smoking, sleep apnea, chronic lung disease, testosterone use) before pursuing primary polycythemia workup. 1