In a 26‑year‑old woman taking buspirone, levothyroxine, liothyronine, milnacipran, and omega‑3 fish oil who has a hematocrit of 45.7%, what is the appropriate management?

Management of Hematocrit 45.7% in a 26-Year-Old Woman

No intervention is needed for this patient's hematocrit of 45.7%, as it falls within the normal physiological range for women and does not meet any threshold for therapeutic action.

Normal Reference Ranges and Context

• The normal hematocrit range for menstruating females is 41 ± 5% (range 36–46%), while post-menopausal females typically have values of 47 ± 6% (range 41–53%). 1
• This patient's hematocrit of 45.7% is at the upper end of normal for a menstruating woman but does not exceed the diagnostic threshold for erythrocytosis. 1
• Her hemoglobin of 15.0 g/dL is also within normal limits (normal range for menstruating females: 14.0 ± 2.0 g/dL). 1

Diagnostic Thresholds for Erythrocytosis

• True erythrocytosis in women is defined as hemoglobin >16.5 g/dL or hematocrit >48–49%. 1
• This patient does not meet criteria for erythrocytosis, as her values are below these thresholds. 1
• The slightly elevated hematocrit relative to the mean likely represents normal physiological variation rather than pathology. 1

Medication Review

• Oral contraceptives (Mili) do not cause erythrocytosis; in fact, they may slightly lower hematocrit through hemodilution effects. 1
• Levothyroxine and liothyronine replacement for hypothyroidism do not independently elevate hematocrit when appropriately dosed. 1
• Buspirone (anxiolytic) has no known effect on red blood cell production. 1
• Omega-3 fish oil does not increase hematocrit but may have antiplatelet effects, which is relevant given her borderline-high platelet count of 368 × 10⁹/L. 2, 3

Supporting Laboratory Findings

• Her RBC count of 5.17 × 10¹²/L, MCV of 88.4 fL, and MCH of 29.0 pg are all within normal limits, indicating normocytic, normochromic red cells without evidence of iron deficiency or other red cell abnormality. 1
• The normal RDW of 13.1% excludes significant red cell size variation that might suggest underlying pathology. 1
• Her platelet count of 368 × 10⁹/L is mildly elevated but does not suggest a myeloproliferative disorder in the absence of other findings. 4

When to Reassess

• Repeat hemoglobin and hematocrit measurements are indicated only if values rise above 16.5 g/dL (hemoglobin) or 48% (hematocrit) on future testing. 1
• If future values exceed these thresholds, workup should include JAK2 mutation testing (both exon 14 V617F and exon 12), serum erythropoietin level, and evaluation for secondary causes of erythrocytosis. 1
• Serial monitoring every 6–12 months would be appropriate only if hematocrit trends upward toward 48% or if symptoms develop. 1

Common Pitfalls to Avoid

• Do not perform therapeutic phlebotomy at this hematocrit level—phlebotomy is indicated only when hematocrit exceeds 65% with documented hyperviscosity symptoms after excluding dehydration. 1, 5
• Avoid unnecessary hematologic workup (bone marrow biopsy, JAK2 testing, erythropoietin levels) when values are within normal physiological range. 1
• Do not misinterpret normal upper-range values as pathological—the hematocrit of 45.7% represents the 95th percentile of normal, not disease. 1

Cardiovascular Risk Considerations

• The optimal hematocrit range for cardiovascular health is 39–45%, and this patient's value of 45.7% is just above the upper end of this range but does not confer increased thrombotic risk in the absence of polycythemia vera. 6
• Her lipid panel shows borderline-high total cholesterol (203 mg/dL) and LDL (122 mg/dL), which are more relevant cardiovascular risk factors than her hematocrit. 6
• Maintaining hematocrit <45% is critical specifically for patients with polycythemia vera to reduce thrombotic events, but this threshold does not apply to healthy individuals with physiologically normal values. 4, 6