The autonomic nervous system is a department of the nervous system that regulates the activity of internal organs, glands of internal and external secretion, blood and lymph vessels. It plays a leading role in maintaining the constancy of the internal environment of the body and in the adaptive reactions of all vertebrates.
The Kerdo index is an indicator used to assess the activity of the autonomic nervous system. If the value of this index is greater than zero, then they say about the predominance of sympathetic influences in the activity of the autonomic nervous system, if less than zero, then about the predominance of parasympathetic influences, if equal to zero, then this indicates functional equilibrium.
The Kerdo index will be greater than zero if the pulse is greater than the diastolic pressure, equal to zero if they are equal and less than zero if the DBP exceeds the pulse.