Fig. 2.

Systems view of transitions from wellness to disease. The systems view recognizes that biological networks maintain wellness but as they become perturbed through aberrant nodal and element dysfunction they drive a pathobiological process that begins with preclinical status, moving to subclinical, prodromal and then manifest disease. The distinction between periods of asymptomatic and symptomatic delimit only that individuals recognition of somatic changes but importantly the network dysfunction can substantially antedate clinical signs and/or symptoms