Iron deficiency

Last updated: Wednesday, 15, December, 2010
CausesAppropriate Tests

Review clinical findings, FBC, blood film; see Anaemia - hypochromic, microcytic.

Iron deficiency can be present before the development of anaemia; the red cell indices and blood film are more sensitive indicators than is the Hb.

Ferritin provides the most sensitive measure of iron stores; low ferritin is diagnostic of iron deficiency, however normal levels may occur when iron deficiency is associated with inflammation or neoplasia.

Iron/iron binding capacity and transferrin saturation may distinguish iron deficiency from the anaemia of chronic disease, but as they may co-exist, a more specific test for iron deficiency is the ratio of plasma soluble transferrin receptor to serum ferritin.

See Table 3 Interpretation of the results of iron studies

Alternatively, a trial of oral iron therapy offers a more practical approach.

Chronic blood loss, especially

This is the commonest cause of iron deficiency anaemia and may be occult; uterine and gastrointestinal blood loss, in particular, should be considered.


See under Vaginal bleeding

Gastrointestinal malignancy

Parasitic infection, especially

  • Hookworm infection

See Worm infection

Intravascular haemolysis e.g. mechanical heart valves

Increased iron requirements, especially




Malabsorption, especially

  • Post-gastrectomy

Dietary deficiency

An uncommon cause in developed countries, but may be seen in the elderly and may be a contributing factor in pregnancy, debilitating illness and alcoholism.