Clinical investigations from the RACP

Diagnosis and evaluation of iron-deficiency anaemia

Stephen JN Tattersall, Christopher S Pokorny



The diagnosis of iron-deficiency anaemia should initiate investigation into the cause. Gastrointestinal bleeding is the most common cause in men and postmenopausal women, and endoscopic evaluation of patients with iron-deficiency anaemia is useful.

Key Points

  • Iron-deficiency anaemia is a common condition that is usually identified by the presence of microcytic, hypochromic red cells and characteristic abnormalities of iron studies.
  • A low serum ferritin level is the most specific serological marker of iron deficiency but it may be elevated in patients with inflammation, liver disease or malignancy.
  • Faecal occult blood testing (FOBT) is a useful screening test for colon cancer in asymptomatic patients but is rarely useful in the setting of iron-deficiency anaemia.
  • Initial endoscopic evaluation of patients with iron-deficiency anaemia includes gastroscopy with small bowel biopsy and colonoscopy.
  • In one-third of patients no cause for iron-deficiency anaemia is found on gastroscopy or colonoscopy and for these patients capsule endoscopy is available on the Pharmaceutical Benefits Scheme within six months of these negative tests.
  • Iron deficiency in the absence of anaemia is less likely to have a sinister gastrointestinal cause.
  • Oral iron supplementation is generally well tolerated by patients, and absorption and haematological response are improved by concurrent administration of vitamin C and folate, respectively.