PT - JOURNAL ARTICLE AU - Sonia Bouri AU - John Martin TI - Investigation of iron deficiency anaemia  AID - 10.7861/clinmedicine.18-3-242 DP - 2018 Jun 01 TA - Clinical Medicine PG - 242--244 VI - 18 IP - 3 4099 - http://www.rcpjournals.org/content/18/3/242.short 4100 - http://www.rcpjournals.org/content/18/3/242.full SO - Clin Med2018 Jun 01; 18 AB - Iron deficiency anaemia (IDA) is an important, common clinical condition and 8–15% of these patients will be diagnosed with a gastrointestinal cancer. IDA is defined as haemoglobin below the lower limit of normal, in the presence of characteristic iron studies. This article will discuss the causes and clinical diagnosis of iron deficiency, including interpretation of common laboratory tests that differentiate this from other causes of anaemia. We suggest an initial approach for investigating the cause of iron deficiency in these patients and also consider the subsequent treatment and indications for further investigation.