twitchy

This term describes a state of high tension where the body or mind is on a hair-trigger. In a physiological sense, it refers to the actual physical manifestation of spasms, often linked to fatigue or neurological stress. It suggests a lack of control over one's own muscles.

Psychologically, the word conveys a sense of jittery instability. It is frequently used to describe someone who is paranoid or overly anxious, implying they are likely to react impulsively or jump at the slightest noise. It carries a more erratic and unstable connotation than simply being nervous.