Stephen French and Arun Kochhar explain how to interpret blood results
The full blood count is one of the most common medical investigations, and it can give important information to help support or refute a diagnosis that doctors have made based on clinical history and examination. The full blood count gives information about red cells (erythrocytes), white cells (leucocytes), and platelets.
Normally the cell counts are maintained in a steady state because the number produced by bone marrow (in haemopoiesis) is similar to the number destroyed by the reticuloendothelial system (the spleen, liver, and bone marrow). When this steady state is disrupted, cell counts may become abnormally increased or decreased.
Red blood cells have a lifespan of about 120 days, in which they transport oxygen from the lungs to body tissues and carbon dioxide back to the lungs. The kidneys produce the hormone erythropoietin, which stimulates the bone marrow to produce red blood cells.
Anaemia occurs if the concentration of haemoglobin