Every now and then, a doctor may prescribe you to have a full blood count, or FBC, (sometimes referred to as complete blood count, CBC) test done. This is usually carried out as part of the screening process to make a diagnosis, or may also be carried out as a routine check-up or to monitor the effect of medication on a particular condition. An FBC looks into several aspects that may affect our health and well-being including possible infection, inflammation, bleeding, anaemia and other deficiencies, as well as detection of disorders such as autoimmunity, sickle cell disease, thalassaemia, leukaemia and bone marrow disorder.

Blood is the medium for transporting blood cells (red blood cells, white blood cells and platelets), antibodies, proteins such as haemoglobin (which transports oxygen to tissues and organs), hormones, vitamins and other nutrients to the rest of the body. An FBC is carried out by drawing a sample of blood from the patient and measuring the levels of these parameters against a given reference range. Studying the results of an FBC may help to identify certain medical conditions, or determine if and how any ongoing treatment ought to be changed.

Let’s take a closer look at what we usually look at in an FBC report. Table 1 shows the parameters that are tested for and discusses potential reasons for increase or decrease beyond the respective reference ranges. The reference ranges (for adults) mentioned here are those followed by my family GP. Please note that reference ranges may vary slightly from one laboratory to another, so it is best to get your test done at a diagnostics centre recommended by your doctor.

Cover illustration adapted from WDRfree