Libido refers to one's appetite for sex; it is also known as the sex drive. It is determined by several factors including the psychological, biological, health, and social well-being of a person. Biological causes of libido fluctuations include testosterone levels and hormonal imbalances. Psychological conditions, such as stress and personality disorders, can also affect an individual's sex life. One's social environment and health also have direct implications on a person's libido. If the community frowns upon sex, then it can affect individual sex appetites in the same way that relationship issues do.