Anaemia is defined as a low haemoglobin (Hb) concentration, which can be either due to a reduced RBC mass or increased plasma volume (e.g. in pregnancy)

– It is <135g/L for men and <115g/L for women

– Subdivided by the mean corpuscular volume (MCV) into microcytic (MCV<80um3), normocytic (80-100) and macrocytic (MCV > 100).

Symptoms:

– Weakness, fatigue and dyspnea

– Pale conjunctiva and skin

– Headaches + light headedness

– Angina –> especially if there is pre-existing coronary artery disease (+ aortic flow murmur)

– Can be signs of a hyperdynamic circulation due to compensation (tachycardia, heart enlargement). But if this is left untreated for too long, it can lead to heart failure.

General Diagnostic pathway:

It is important to look at the MCV to narrow down the aetiology.

– If microcytic –> do iron studies

– If macrocytic –> check blood film to distinguish megaloblastic and normoblastic anaemia.

– If normocytic –> look at the reticulocyte count.

–> If ­reticulocyte count is raised, this implies there is a destructive problem

–> If reticulocyte count is low, this implies there is a production problem or early blood loss (as the bone marrow has not had enough time to compensate).