The full blood count is the most commonly ordered laboratory test in Nigeria and one of the most informative. It is also the one people most often receive as a page of abbreviations and numbers with no explanation attached.
This guide walks through what each main value describes, what raised or lowered results can suggest, and, importantly, why a single out-of-range number is rarely the whole story.
The red cell values
Red cells carry oxygen. The red cell portion of an FBC tells you how much oxygen-carrying capacity you have and offers clues about why it might be reduced.
- Haemoglobin (Hb): the oxygen-carrying protein itself, and the primary marker for anaemia.
- Packed cell volume (PCV) or haematocrit: the proportion of your blood made up of red cells. It usually moves with haemoglobin.
- Red cell count (RBC): how many red cells are present.
- MCV: average red cell size. Small cells often point toward iron deficiency, large cells toward vitamin B12 or folate deficiency.
- MCH and MCHC: how much haemoglobin the average cell carries, which refines the picture further.
Low haemoglobin can indicate anaemia, but anaemia is a finding rather than a diagnosis. Possible causes include iron deficiency, blood loss, chronic disease, infection and inherited blood disorders. Red-cell indices such as MCV provide additional context, which is why the overall pattern matters more than one number.
The white cell values
White cells are your immune system. The total count tells you whether the system is activated, and the differential, which breaks the total into cell types, hints at what activated it.
- Neutrophils: usually rise in bacterial infection and acute inflammation.
- Lymphocytes: often rise in viral infection, and are the cells most relevant in some chronic conditions.
- Monocytes: rise in chronic infection and during recovery phases.
- Eosinophils: may rise with allergic conditions, parasitic infection and some other disorders.
- Basophils: the smallest fraction, occasionally raised in specific conditions.
A raised total white cell count with high neutrophils suggests a different story than a raised count driven by lymphocytes. Neither is a diagnosis on its own, but together with symptoms they narrow the question considerably.
A low white cell count can follow certain viral infections, some medications, and a number of other conditions. It is a finding that should be interpreted with a clinician rather than assumed to be serious or ignored.
Platelets
Platelets are the cell fragments that form clots and stop bleeding. Both directions matter.
A low platelet count can increase bleeding risk, especially when the count is markedly reduced. Possible causes include infections, medications, immune conditions, bone-marrow disorders and other illnesses. The result needs interpretation alongside symptoms and the rest of the blood count.
A raised platelet count can be reactive, following infection, inflammation, iron deficiency or surgery, and often settles as the underlying cause resolves.
How to read your own report
Every laboratory prints reference ranges beside your results, and those ranges are specific to that laboratory's methods and population. Compare your value against the range printed on your own report rather than one found online.
Ranges also shift with age, sex and pregnancy. Haemoglobin norms differ between men and women and change during pregnancy, so a value flagged low may be entirely expected in context.
Marginal results just outside a range are common and frequently unimportant. What clinicians pay attention to is the size of the deviation, the pattern across related values, whether it is changing over time, and whether it matches your symptoms.
When to act on a result
See a clinician promptly if your haemoglobin is significantly low, if your platelet count is markedly reduced, if white cells are substantially outside range, or if any abnormal result comes alongside fever, breathlessness, chest pain, unexplained bruising or bleeding.
For a borderline result, a clinician may recommend repeat testing, review of previous results or other follow-up depending on your symptoms and context.
Whatever the result, have it interpreted in context by an appropriately qualified healthcare professional. The Life Centre team can help with the practical next step or coordinate with your clinician where appropriate.
