The routine use of serum bilirubin determinations on nonjaundiced patients discloses a group in which the serum bilirubin value is elevated beyond the usually accepted normal figure but in which there has been no evidence of preceding or subsequent jaundice. Such a group may be said to have latent jaundice.
The presence of an isolated elevated serum bilirubin value in a case in which the routine diagnostic survey discloses no other abnormality imposes certain diagnostic responsibilities on the clinician. Shall he ignore the hyperbilirubinemia? In terms of milligrams per hundred cubic centimeters of blood, at what level should one infer that a given value represents hyperbilirubinemia? Naturally the average patient, seeking relief from some real or fancied ailment, does not represent a normal individual, and a large group of similar patients, by virtue of the size of the group alone, cannot be considered a cross section of normal individuals. Nevertheless