Hemolytic Anemia - Basic Features

Basic Features

Hemolytic anemia involves the following:

1. Abnormal and accelerated destruction of red cells and, in some anemias, their precursors
2. Increased breakdown of hemoglobin, which may result in:
   1. increased bilirubin level (mainly indirect-reacting) with jaundice
   2. increased fecal and urinary urobilinogen
   3. Hemoglobinanemia, methemalbuminemia, hemoglobinuria and hemosiderinuria (where there is significant intravascular hemolysis).
3. Bone marrow compensatory reaction:
   1. Erythroid hyperplasia with accelerated production of red cells, reflected by reticulocytosis, and slight macrocytosis in peripheral blood
   2. Expansion of bone marrow in infants and children with severe chronic hemolysis - changes in bone configuration visible on X-ray
4. The balance between red cell destruction and marrow compensation determines the severity of anemias.