The autonomic nervous system (ANS) provides homeostasis due to the innervation of the secretory glands, smooth muscle and cardiac muscle. Higher centers of the ANS (primarily the hypothalamus, some centers of the brain stem and limbic system) form a integrative network, which plays a key role in coordinating the functioning of the endocrine, immune system and other parts of the central nervous system. Intracranial centers of the ANS are responsible for the consciousness, behavioral, emotional, and other components of the higher nervous activity. Thus, the significance of the ANS can't be overestimated. At the same time today in neurointensive care there are no clear criteria for ANS dysfunction, we don't have universally recognized monitoring facilities for ANS and approaches to targeted therapy of its disorders. This paradox is even more important as in the pathogenesis of some critical conditions such as neurogenic pulmonary edema, stunned myocardium, cardiomyopathy Takotsubo lies precisely ANS imbalance. This review devoted to the ANS and some problems associated with its imbalance.