This document provides an overview of approaches to classifying and diagnosing anemia. It defines anemia and outlines important factors to consider, such as looking for the primary cause. Anemia is classified based on pathogenesis and etiology into categories like blood loss, impaired red cell formation, and impaired red cell destruction. Mean corpuscular volume (MCV) is used to classify chronic anemias as microcytic, normocytic, or macrocytic. Differential diagnoses are considered based on additional laboratory findings and clinical presentation for each type. General evidence of hemolysis is also outlined.

1. Approach to Anemia

2. Definition
A reduction in the concentration of
hemoglobin in the peripheral blood below
the normal for the age and sex of the patient
Male 13 g/dl
Female 11 g/dl

3. Important to Remember:
• Anemia is a symptom and not a disease
• Look for the Primary Cause!

4. Classification (Pathogenesis & etiology)
• Blood Loss
– Acute
– Chronic
• Impaired red cell formation
– Defi of essential subs
– Others
• Impaired red cell destruction
– Hemolytic anemia – Intrinsic abnormality
– Hemolytic anemia – Extrinsic abnormality

5. What is the mean corpuscular volume (MCV )
Classify chronic anemia as:
Microcytic (decreased MCV )
Normocytic (normal MCV )
Macrocytic (increased MCV )

6. Anemia
MCV
Blood smear
MCV >100 MCV 80-100 MCV <80
Macrocytic Normocytic Microcytic

7. Macrocytic Anemia
Blood & BM Morphology
Hemolytic An Alcoholism
Hemorrhage Hepatic dis.
MDS
Non-Megaloblatic
Clinical data; serum vitamins
Folate Deficiency Reticulocytes
No deficiency
B12 deficiency
N /Decreased
Increased
Hypothyroidism
Congenital
Drugs
Schilling test
with IF
Diet
Corrected Not Corrected
Good Poor
Megaloblatic

8. Microcytic anemia
Microcytic anemias usually as result of
defective hemoglobin synthesis
Differential:
• Iron deficiency
• Thalassemia trait
• Anemia of chronic disease
• Sideroblastic anemia

9. Iron Deficiency vs Thalassemia
Hb MCV RDW
Thalassemia Normal/Slight
ly decreased 65 Normal
Fe
deficiency
Decreased 65 Increased

10. Hypochromic & /or Microcytic Anemia
Serum Iron
Thalassemia Sideroblastic An
Hemoglobino
pathies
Congenital
Acquired
Iron
deficiency
Normal Increased
Reduced
Hb Electrophoresis BM sideroblastic Fe
increased
S Ferritin
BM Iron
An of
chronic
disorders
Low
Normal or
increased
Increased
Absent

11. Normocytic Anemia
Reticulocytes
BM
Negative
screens
ACD
Hemolytic
An
Normal or decreased
Increased
Post
hemorrhagic
History, Course, PBS, Bile
pigment
Screen for renal,
hepatic, endocrine dis.
Serum
Iron
Normal or
High
Low
Early
IDA
Hypoplastic An
MDS
Infiltration

12. General Evidence of hemolysis
• Evidence of Increase Hb breakdown
– Jaundice & hyperbilirubinemia
– Reduced haptoglobin & hemopexin
– Increase LDH
• Evidence of compensatory hyperplasia
– Reticulocytosis
– Erythroid hyperplasia
– X-ray
• Evidence of RBC damage
– Spherocytosis & Increased RBC fragility
– Fragmentation