Last updated: Wednesday, 27, October, 2010
CausesAppropriate Tests

FBC. Blood film.

Further investigation is guided by review of clinical features, red cell indices (MCH, MCHC, MCV) and report on blood film.

Anaemia is often multifactorial - consult pathologist.

Hypochromic, microcytic  (MCV <80 fl) 

Full iron studies may be indicated to establish cause.

See Table 3. Interpretation of the results of iron studies

Iron deficiency anaemia 

Diagnosis made on low ferritin but may be difficult when associated chronic disease with raised serum ferritin e.g. in rheumatoid arthritis.

Ratio soluble transferrin receptor/serum ferritin may be useful in some cases where iron studies are ambiguous.

See iron deficiency


Sideroblastic anaemia (hereditary)

Normochromic, normocytic

Polychromasia not evident

Absolute reticulocyte count is usually normal, but may be low.

Anaemia of chronic disease/ Anaemia of inflammation

Early iron deficiency

See iron deficiency

Dilutional anaemia, especially

  • 'Physiological' anaemia of Pregnancy
  • Fluid overload, especially
         Cardiac failure

Further investigation is not usually indicated.


  • Non-spherocytic haemolytic anaemia

See anoraxia nervosa

Haemolysis with impaired bone marrow response 

See Haemolysis.

Acute blood loss, prior to marrow response 

Clinical diagnosis; serial PCV may be of value.

Artefactual result 

See Table 1: Artefactual Results.

Normocytic with polychromasia

Reticulocyte count, if documentation of reticulocytosis is required for diagnosis or monitoring.

Anaemia of acute blood loss 

Clinical diagnosis; serial PCV may be of value.

Haemolytic anaemia 

See Haemolysis.

Normochromic, macrocytic


Hepatic failure

Chronic hypoxic lung disease 

Macrocytosis with a normal or increased Hb (erythrocytosis).

With round macrocytes

Anaemia of bone marrow failure/infiltration, especially

Tear drops (dacrocytes) often prominent. Bone marrow aspiration and trephine biopsy, as indicated. The anaemia may be normocytic, rather than macrocytic.

  • Myelodysplasia
See myelodysplastic syndromes
  • Disseminated carcinoma 

See also Leucoerythroblastic anaemia.

With oval macrocytes especially

Megaloblastic anaemia

See also Megaloblastic anaemia.

  • Drug-induced
  • Double deficiency iron and vitamin B12/folic acid
  • Hypothyroidism

Anaemia, if present, is usually mild.

Paroxysmal nocturnal haemoglobinuria

Lymphoma, multiple myeloma

Endocrine disorders

Marrow dysfunction