Sexual dysfunction is broadly defined as the inability to fully enjoy sexual intercourse. Doctors divide normal sexual function into 3 phases: desire (you want to have sex), arousal (your body undergoes the physical changes that allow you to have sex), and orgasm. Sexual dysfunction occurs when your health, your relationship, or your ideas about sex cause problems in any of these phases. This is true for men and women. Pain during sex can also cause sexual dysfunction, especially for women.