Gender issues refer to unequal treatment or perceptions of individuals based on their gender. Gender is defined as the characteristics that a society delineates as masculine or feminine, while sex refers to male and female biological characteristics. Gender inequality arises from differences in socially constructed gender roles. Gender issues include gender-based violence such as domestic violence, sexual violence, and human trafficking. Violence disproportionately affects women and girls worldwide and has significant health, social, and economic costs including physical and mental health problems, lost productivity, and economic losses.