Keywords: Haemolytic anaemia


Appropriate Tests


Full blood count, Blood film, Reticulocyte count, Bilirubin, Lactate dehydrogenase. Haptoglobin may be useful for documentation and monitoring.

If acute intra-vascular haemolysis suspected: Schumm's test; Haemoglobin urine.

If chronic intravascular haemolysis suspected: Haemoglobin urine.

Active haemolysis may be present without anaemia if bone marrow reserve is sufficient.

See also Haemolysis (neonatal)

With red cell spherocytosis

Direct antiglobulin test.

Further investigation - consult pathologist.

Autoimmune haemolysis, including

  • Incompatible transfusion
  • Haemolytic disease of the newborn


See Immediate and delayed transfusion reactions under Blood transfusion - complications.

Hereditary spherocytosis


Severe burns

Blood film may also show red cell fragmentation.

Clostridium perfringens septicaemia


With red cell fragmentation ± spherocytosis


Microangiopathic haemolysis


Drug-induced oxidative haemolysis, especially

  • Salicylazosulphapyridine
  • Dapsone
  • Phenacetin
  • Primaquine

Heinz body preparation ± Methaemoglobin, Sulphaemoglobin.

Consider possibility of underlying intrinsic red cell defect.


Particularly in patients with G-6-PD deficiency.

Intrinsic red cell defects, especially


  • Haemoglobinopathy - unstable

Unstable haemoglobin screening test, Haemoglobin electrophoresis.

  • G-6-PD deficiency


  • Pyruvate kinase deficiency

Pyruvate kinase - red cell assay.

  • Other red cell enzyme deficiency

Autohaemolysis test, further investigation in specialised laboratory.

With sickle cells


Sickle cell disorders


With normal red cell morphology




Paroxysmal nocturnal haemoglobinuria (PNH)

Flow cytometry evaluation; Paroxysmal nocturnal haemoglobinuria

Paroxysmal cold haemoglobinuria

Donath-Landsteiner Ab.

March haemoglobinuria 

Haemoglobin urine, after exercise.

Intrinsic red cell defects

Red cell morphology may be unremarkable in patients with sickle cell trait, G-6-PD deficiency or an unstable haemoglobinopathy, particularly when haemolysis is not active.

See also Haemoglobinopathy and Sickle cell disorders.

With red cell parasites

Parasites blood, Blood film.