"What is Normal?"
Johan Koeslag, Department of Medical Physiology, Tygerberg South Africa
Conforming to a cultural norm.
Medical practitioners would probably be unanimous in condemning this definition [of "normal"] as the basis of their professional decision-making. But it is, in fact the only implied definition of normality in Dorland's Medical Dictionary. The norm, in this case, seems to be the immediate post-pubertal physical state. This applies particularly to the systemic arterial blood pressure, body fat content, glucose tolerance, and plasma lipid profiles, all of which change with age. Though these changes are the rule, they are seldom considered to be normal. Indeed there are, in Medicine, almost no unreservedly age-specific normal values for middle- and old-aged persons. All age-related deviations from the immediate post-pubertal state are considered degenerate, and abnormal.
Other cultures consider anyone under middle age as still in the immature, developmental stage. Their normal physiological values, if they were to compile them, would reflect the physiology of 50 year-olds, and relegate our culture's normal values to the Paediatric category.