Investigation and management of anaemia

Anaemia is not a disease but is a manifestation of some other process. Once a deficiency of iron, vitamin B12 and folic acid has been excluded, the anaemia may be secondary to another pathology, and causes such as infection, inflammation, neoplasia, drug or chemical exposure or an autoimmune disorder sought. The approach should be to obtain details of the patient’s personal and family history, ethnic origin, dietary and drug history and examination, and, to use simple laboratory tests to determine the type of anaemia. This will often provide a provisional diagnosis, and can be confirmed by measurements of iron, vitamin B12 and folate levels, reticulocyte count, haemoglobin electrophoretic studies and a bone marrow examination. Once the anaemia and its cause have been established, simple guidelines are provided for treating the various abnormalities. A ‘shot gun’ approach is not recommended and may confuse the issue if treatment fails. Defining the type of anaemia means that specific therapy, whether replacement or directed against a defined abnormality, will usually suffice. Failure to obtain the expected response, provided the patient is complying with treatment, requires a review of the history, examination and laboratory results.