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. Many researchers use the term state self esteem to refer to the emotions we are feeling at a point in time, and trait self-esteem to refer to the way people generally feel about themselves.
The State Self Esteem Scale (SSES) a 20-item scale that measures a participant’s self-esteem at a given point in time, and can therefore be measured on a regular basis, recognising the notion that self-esteem is open to momentary changes.
Heatherton, T. F. & Polivy, J. (1991)