Low Self-esteem is an individual's subjective evaluation of their own worth. Self-esteem encompasses beliefs about oneself (for example, "I am unloved", "I am worthy") as well as emotional states, such as triumph, despair, pride, and shame. Smith and Mackie (2007) defined it by saying "The self-concept is what we think about the self; self-esteem, is the positive or negative evaluations of the self, as in how we feel about it."

Self-esteem is an attractive psychological construct because it predicts certain outcomes, such as academic achievement, happiness, satisfaction in marriage and relationships and criminal behavior.

Self-esteem can apply to a specific attribute (for example, "I believe I am a good writer and I feel happy about that") or globally (for example, "I believe I am a bad person, and I feel bad about myself in general"). Psychologists usually regard self-esteem as an enduring personality characteristic (trait self-esteem), though normal, short-term variations (state self-esteem) also exist. Synonyms or near-synonyms of self-esteem include many things: self-worth, self-regard self-respect, and self-integrity.