perturbation

an unhappy and worried mental state; "there was too much anger and disturbance"; "she didn''t realize the upset she caused me"

(physics) a secondary influence on a system that causes it to deviate slightly

activity that is a malfunction, intrusion, or interruption; "the term `distress'' connotes some degree of perturbation and emotional upset"; "he looked around for the source of the disturbance"; "there was a disturbance of neural function"

a disposition that is confused or nervous and upset

the act of causing disorder