perturbation

(n) an unhappy and worried mental state
- there was too much anger and disturbance
- she didn't realize the upset she caused me
upset, disturbance,
(n) (physics) a secondary influence on a system that causes it to deviate slightly
(n) 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
disturbance,
(n) a disposition that is confused or nervous and upset fluster,
(n) the act of causing disorder disruption,

upset disturbance fluster disruption