Abstract
The constrained disorder principle defines the existence and function of living organisms. The principle specifies that biological systems comprise a disorder within constrained random boundaries. Per this principle, living organisms are machines with a degree of error that do not strive to optimize. Their differentiator from non-living organisms is their intrinsic disorder within personalized dynamic random boundaries. The constrained disorder is mandatory for the systems' existence and proper operation. It provides living organisms the flexibility and adaptability required for operating under continuously changing internal and external milieus. The constrained disorder principle defines health and disease states by specifying the degree of the disorder and the arbitrary boundaries of biological systems. Disturbed systems lose their disorder or operate out of the disorder boundaries leading to diseases. The principle provides a platform for applying the constrained disorder to correct systems disturbances and improve disease outcomes.