Sexual dysfunction is defined as the inability to perform within the norm of human sexual behavior for as period of six weeks or longer. Between 24 and 33% of the general population (not including a geriatric subgroup) experience the clinical definition of sexual dysfunction.
This clinical definition is not always helpful. The term dysfunction categorizes as "abnormal" or "inadequate" a variety of sexual activities and responses that many cultures in other parts of the world and sub-cultures here view as normal. Additionally many things that are now viewed as standard, such as clitoral orgasms, were once thought to be pathological; desires once classified as perverse, such as homosexuality, are now viewed as part of a normal range of human sexuality.
Perhaps it is more beneficial to think about sexual satisfaction. Ninety-five to ninety-nine percent of the general population will experience sexual dissatisfaction in their lifetime. Ask yourself a fundamental question -- "Is my sexual behavior satisfying to me and whatever sexual partners I want to please?" If you find that you are continually disappointed, alienated, inhibited, or frustrated during your sexual activities, then exploring some form of therapy may be a good option. A pattern of behavior or a physical condition might be said to be "dysfunctional" only if it doesn't work for you. For additional information see "Erectile Dysfunction" and "Premature Ejaculation" in the Men's Health section.