AMONG the many pitfalls to which the physician is exposed, the interpretation of normalcy as it applies to clinical data continues in increased importance. Prolonged, usually expensive, and sometimes dangerous therapeutic programs are often pursued in response to the patient's demand for relief of an obscure symptom. These programs often originate in the mistaken interpretation of results of a given laboratory procedure as "too low" or "too high," the import reflecting a pathologic alteration of the related tissue or viscera. The article published by Wilson and Boyle in the present issue of the Archives forcibly calls attention again to this dilemma as it applies specifically to the evaluation of red blood cell counts.
It appears necessary to be reminded again of the fact that the red cell count gives only an estimate of the number of cells per unit volume of blood. Consequently, an increase or decrease in the red