The Effect of Habitual Smoking on White Blood Cell Count

It would be widely accepted that leucocyte counts in healthy people range approximately from 4, 000 through 9, 000/mm In daily clinics, however, we often come across cases with the leucocyte counts well exceeding the range. Aside from clinical observations, about 3% of 12, 000 and odd healthy Japanese were found having their leucocyte counts over 10, 000/mm^3 in our previous studies. Most of them failed to show any trace of inflammation or any other clinical manifestations, making us puzzled about the reason. We have studied cases with asymptomatic leucocytosis and found that it is closely related to habitual smoking