Normal blood picture

The normal blood picture is normal. This statement sounds obvious - but, what does it mean?
The difference between normal and pathological is not always easy. It is, therefore, important to recognize artifacts as such and not to attribute any pathological importance to them. Artifacts occur when too much time elapses between venipuncture and processing (e.g. the autocytolysis of neutrophils), when mistakes in processing are made (e.g. crushed cells) or during staining (e.g. bluish red cells due to the staining solution being too basic).
Normal values are determined by the Gaussian normal distribution, i.e. 5% of the population are outside the upper and lower ends of the normal range. This means that 10% of the "norms" will have pathological values.

Look up normal values.