HSDD

A recent survey of American women ages 18-59 found that the most common sexual problem in women is hypoactive sexual desire disorder - HSDD, more commonly referred to as low sex drive or libido, followed by difficulty with orgasm. Pain during intercourse--which occurs in 14.4 percent of women--was the only condition to show a relationship to age -- it decreases as women get older.
HSDD is a deficiency or absence of sexual fantasies and desire for sexual activity, as defined by the American Psychiatric Association (APA). The definition is vague because the APA acknowledges that there can be significant differences in sexual interest levels among women. According to the survey mentioned above, 37% of women think about sex a few times a month and only 33% think about sex 2-3 times a week or more. Happier women seem to think about sex more often than unhappy women.
Difficulty with orgasm, or female orgasmic disorder, is a persistent delay or absence of orgasm. This definition is also from the APA and it again attempts to allow for individual variation by not giving a specific number or percentage to define a "normal" amount of orgasms. The survey states that 29% of women say they always have orgasms during sex and 40% say they are physically satisfied with their partners.
There are wide variations in sexual functioning, and there is no gold-standard that women should feel they must meet for their sexual functioning to be considered 'normal.' If a woman experiences a sexual problem that troubles her, then it is a problem that needs to be addressed and she should be encouraged to talk to her doctor about it to see how it can be improved.