Quality of life is equated with overall enjoyment of life. In medical studies, quality of life is measured using various standardized questionnaires to rate such factors as pain, treatment side-effects, mood, energy level, family and social interactions, sexual function, ability to work, and ability to keep up with routine daily activities. The term is used to describe an individual’s satisfaction with his or her life and general sense of well-being. It is often measured as physical, psychological and social well-being.