The full blood count (FBC) test shows you an indication of both general health and immune system. The blood test checks the health of your red blood cells, white blood cells and platelets. This is important if you have inherited blood disorders or if you are experiencing symptoms of anaemia such as feeling tired, pale skin or fatigue. By examining your white blood cells, the test can also detect recent or current signs of inflammation or infection. Platelets are related to your coagulation ability.