There is then an appropriate algorithm to discover the cause of each of these categories, but in the case of normocytic anaemias, the list is rather short. So long as you're not considering aplastic anaemias or a pancytopenia, there are basically only three causes; the odds of it not being one of the following three are vanishingly small:
- Anaemia of chronic disease
- Renal failure
- Acute blood loss
It's not often that medicine hands you such a short list, so grab it with both hands!