Abstract: This invention relates to constructing a reference tool and using the reference tool for distinguishing between a medical condition of a subject and a reference subject. This tool may be considered as a reference “map” consisting of one or several numbers of reference groups, where the subjects within the same groups share one or more common characteristics, e.g. age, sex, medical condition, etc. The present invention therefore relates to seeing whether a subject to be diagnosed falls within one or more of said groups simply by comparing processed biological data collected from the subject with the reference “map”.