Anemia Summary

Anemia Diagnostic steps

  1. CBC: HCT
    • Iron Def: M - <135; F - < 115
  2. CBC: MCV
  3. If microcytic
    1. CBC: RDW
    2. If Iron deficiency - blood = 0.5 mg Fe/mL (~1/2 of blood is RBC)
      1. Serum ferritin (Bone marrow aspiration gold standard)
        1. Even if ferritin is normal patient can still be anemic because in inflammation, serum ferritin levels rise (more ferritin is released)
      2. peripheral blood smear has hypochromic, microcytic, (and target) cells
      3. Others such as TIBC, T sat, etc are more unreliable (fluctuate with diet, drugs, infections, etc)
  4. If normocytic
    1. Reticulocyte count (stain for RNA) >1%
      • high in hemolysis and acute blood loss. To confirm:
        • Unconjugated bilirubin
        • LDH (high)
        • Haptoglobin (low)
        • (Hemosiderinuria)
        • (Schistocyte)
      • Intrinsic or Extrinsic
      • Spherocytes
        • Burn
        • Autoimmune hemolytic anemia
        • Bacterial infection
        • Diagnostic: DAT (Coombs)
          • Warm (IgG) vs. Cold (IgM)
  5. Treatment
    1. Find root cause!
    2. Iron deficiency: oral, then IV
    3. Hemolytic:
      • Prednisone 1mg/kg
      • Folate supplement
      • Second line: Take out spleen
      • Causes
        • 3L - Lupus, Leukemia, Lymphoma + Medications

Summary of All Anemia

Low MCV <79 fL Normal MCV 79-97 fL Macrocytic >97 fL
Microcytic Anemia Normocytic Anemia Macrocytic Anemia
T halassemia
A nemia of chronic illness
I ron deficiency
L ead poisoning
S ideroblastic
(Myelodysplastic Syndrome (MDS))
Blood loss
Bone marrow/production disorders
Anemia of chronic illness
(Myelodysplastic Syndrome (MDS))
  • Folate/B12 deficiency


  • Liver disease/alcohol
  • Hypothyroidism
  • Reticulocytosis
  • Myelodysplastic Syndrome (MDS)

Differences in RDW

  • Poikylocytosis - different shapes
  • Anisocytosis - different sizes
RDW > 15.0
Iron Deficiency
RDW normal or low
Variability in size of RBCs
Older cells are smaller (MCV low)
Newer cells (reticulocytes) have larger MCV
(In extreme cases, there is no iron, narrow RDW)
Less variability in size of RBCs
New and old cells are both small, due to lack of hemoglobin
(In extreme cases, will get wide RDW - anisocytosis)
In a state of limited resources, resource distribution is not equal
Will get some normal cells, but most will be small
In a state of no resources, everyone is small

Intrinsic Vs. Extrinsic Hemolytic Anemia

Intrinsic Extrinsic
Red cell membranopathies
e.g. hereditary spherocytosis
* G6PD deficiency
* Pyruvate kinase deficiency
* Sickle cell
* Thalassemia
PNH - Paroxysmal noctural hemoglobinuria
Immune mediated
* Autoimmune hemolytic anemia
* Alloimmune hemolytic anemia
Microangiopathic hemolytic anemia
* DIC - Disseminated intravascular coagulation
* Cardiovascular valve damage
* Malaria
* Other intracellular parasites (comes out and cell burst)
Other causes


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