Normality and diseases do not have sharp delineations. It’s quite arbitrary that a label, “disease,” begins with a clinical diagnosis. One may ask: does the disease of lung cancer, for example, begin with the diagnosis or somewhere else along the 30 year trajectory of smoking? Indeed, as diagnostic tools improve, the beginning of each disease is being moved further back along the line of the disease true origin. Then, however, we encounter another paradox, the disease that is diagnosed “early” but later is proven that it has remained “under control” for decades (e.g. some prostate cancers). Health and disease may be just different sides of the same coin; the clinical diagnosis of a “disease” depends heavily on when health care steps in and in a way “freezes” the image of the health/disease ongoing balancing act within the human body.
The Dynamic Systems Model (reference is below) suggests that a system remains in its Health Territory (where it continues to create value as a reflection of its emergence) because of its complex adaptive nature that, in a dynamic fashion, maintains a positive expression of the health/disease oscillating probabilities. Human body can be conceptualized as such a system. Within this Model, the Zone of Chaos expresses the loss of system adaptability/organized complexity and thus heightened probability of disease manifestations such cancer. The opposite zone is marked in the Model as Zone of Entropy where system functionality diminishes and the bodily system is significantly prone to express degenerative diseases.
Increasing the arbitrary expansion of “disease” categorizations, as described in A new deal on disease definition (Moynihan R, BMJ 2011; 342:d2548 doi: 10.1136/bmj.d2548) may be just an expression of persistent conceptual linear approach to health/disease fluctuations within, however, a non-linear system that is the human body. There seems to be a fundamental mismatch.
Janecka IP: Cancer control through principles of systems science, complexity, and chaos theory: A model. Int J Med Sci 2007; 4:164-173. http://www.medsci.org/v04p0164.htm