Clinical medicine would gain from a discussion of the significance of health promotion. Some central concepts are discussed: the diagnostic process; disease prevention vs. health promotion; the practical importance of the understanding of the difference between the 2 concepts health and absence-of-disease. The concept of health catches the intra-personal level, the undisrupted self, whereas absence of disease concerns the proper functioning of the organism, the human biology. By means of comparing 2 diagnoses, multiple sclerosis (MS) and fibromyalgia syndrome (FS), it is argued that there are diagnoses of at least 2 distinct kinds. The diagnosis of MS is similar to a scientific discovery, whereas the diagnosis of FS is constructed more like criminal law. Consequently, diagnosis-based disease prevention and health promotion have to comply with a wide range of reality. Finally, clinical dialogue is pointed out as a method that successfully combines diagnostic, preventive and promotive efforts, as well as clinical care and cure.