[From Chronos to Chaos: from the determinism of circadian rhythm of arterial pressure to the undeterminism of hypertensive crises].

This paper delineates the scientific though about the disorder (chaos) in dynamic phenomena. The discussion shows how the periodic functions, which are intrinsically deterministic, can break down into chaotic patterns, either global or catastrophic, because of their "dependence on the limits in the oscillatory modulation" (cycle stress limits). The argumentations demonstrate that order and disorder, chronos and chaos, are intrinsic aspects of dynamic phenomena. The text presents the fractal mathematics for analysing nonlinear events. The fractal interpolation is proposed for predicting the potential risk of hypertensive crisis using the noninvasive ambulatory blood pressure monitoring.