Lab Interpretation Guide

Anemia Blood Markers — Complete Guide

Hemoglobin · MCV · Ferritin · Iron · B12 · Folate · Reticulocytes

Quick Answer

Anemia diagnosis starts with hemoglobin level. MCV differentiates microcytic (iron deficiency, thalassemia) from normocytic (chronic disease, bleeding) and macrocytic (B12/folate deficiency). Ferritin, iron studies, and B12 confirm the etiology. Always check for masked iron deficiency in inflammation.

Hemoglobin Reference Ranges

Men (adult)
Normal130–170 g/L
Mild110–129
Moderate80–109
Severe< 80
Women (adult)
Normal120–155 g/L
Mild105–119
Moderate80–104
Severe< 80
Pregnancy
Normal110–150 g/L
Mild100–109
Moderate70–99
Severe< 70

MCV-Based Diagnosis

MCV < 80 fL — Microcytic
  • Iron deficiency anemia (most common)
  • Thalassemia (alpha or beta)
  • Anemia of chronic disease (sometimes)
  • Sideroblastic anemia (rare)
Check ferritin, serum iron, TIBC, transferrin saturation, peripheral smear
MCV 80–100 fL — Normocytic
  • Anemia of chronic disease (most common)
  • Acute blood loss
  • Hemolytic anemia
  • Mixed deficiency (B12 + iron)
  • Early iron or B12 deficiency
Check reticulocytes, LDH, haptoglobin, direct Coombs, ferritin, B12
MCV > 100 fL — Macrocytic
  • B12 deficiency (most common)
  • Folate deficiency
  • Liver disease or alcohol excess
  • Hypothyroidism
  • Medications (methotrexate, hydroxyurea)
Check B12, folate, homocysteine, methylmalonic acid, thyroid function, LFTs

Iron Studies — Pattern Interpretation

Iron Deficiency Anemia
Ferritin↓ < 15 ng/mL
Serum Iron↓ Low
Transferrin Sat.↓ < 20%
Anemia of Chronic Disease
FerritinNormal or ↑
Serum Iron↓ Low
Transferrin Sat.Low or normal
Iron + Inflammation (masked)
FerritinNormal (falsely)
Serum Iron↓ Low
Transferrin Sat.↓ < 20%
Iron Overload / Hemochromatosis
Ferritin↑↑ Very high
Serum Iron↑ High
Transferrin Sat.> 45%
Normal
Ferritin15–300 ng/mL
Serum Iron9–30 µmol/L
Transferrin Sat.20–45%

Key Clinical Points

  • Ferritin is an acute-phase reactant — may be falsely normal in iron deficiency with concurrent infection or inflammation
  • Iron masked by inflammation: low serum iron + elevated CRP + normal ferritin = likely iron deficiency despite normal ferritin
  • B12 deficiency causes both megaloblastic anemia AND irreversible neurological damage — treat promptly
  • Elevated homocysteine + MCV > 100 = strong indicator of B12 or folate deficiency even if B12 is borderline
  • RDW > 15% with low hemoglobin suggests mixed etiology or early iron deficiency before MCV drops
  • Reticulocytopenia in anemia suggests bone marrow failure or aplasia — urgent hematology referral
  • In pregnancy, iron deficiency is the most common cause of anemia — ferritin < 30 ng/mL warrants supplementation
Identifying anemia type automatically from blood test?

STRUCTA MED automatically identifies iron deficiency, B12/folate, and anemia of chronic disease patterns — including iron masked by inflammation — with sex and pregnancy-adjusted thresholds.

Analyze Anemia Markers Free