Worry

emotion

Worry is an emotion. It means that one feels stressful or he or she is panicking about something. It is felt as anxiety or concern about a real or imagined issue. Most people experience short periods of worry in their lives, but it is not normally a problem. In fact, a small amount of worrying may even have good effects, if it makes people take precautions or be more careful.

Mental state in terms of challenge level and skill level, according to Mihaly Csikszentmihalyi.[needs simplifying]