It is now a well documented sociological and medical fact - as in data compiled by quite a few reputable sources including the Centers for Disease Control and Prevention, (CDC), the American Psychology Association (APA), the American Medical Association (AMA), and the Association of Couples and Sexual Counseling Practitioners (ACSCP), that the rate and incidence of women who are clinically diagnosed with one of the several forms of hypoactive sexual desire disorder (aka HSDD) has been on a steady increase of about 1.5% of the total female population in the U.S. between the ages of 25 and 50 since the start of the first meta-study in 1995.
This means that now in 2013, an estimated 27% of all women between the ages of 25 and 50 in just the U.S. alone are impacted by some form of chronic HSDD which, by definition of the diagnosis requires a loss of sexual interest, libido, the ability to reach an orgasm, or who have developed a degree of physical discomfort with intercourse itself which prevents them from having a normal and healthy physical / sexual aspect to their relationships.
The underpinning reasons are varied - for some women it stems from the level of stress they are under balancing career, home, duties as a mom, wife, you name it.
Another major cause is the now very widespread use and prescription of several classes of anti-depressant medications such as SSRI's and similar method of action medications. These drugs, such as Lexapro and Celexa, just to name a couple, are notorious for their effect on libido in women.
Another major cause is changes in hormonal balance - something which is most often tied to female menopause.
A little known fact of modern life is the impact that various birth control pills have had on a woman's long term hormonal health and hormone balance. Studies have begun to show that as the first generation of women who are reaching their 40's after a many years on "the pill" that for reasons yet to be fully understood, some women are actually entering a "menopause-light" stage of life as early as their mid to late 30's.
That also wreaks havoc on what we are coming to understand is the very complex chain reaction of requirements which must all come together for a woman to actually feel a strong state of sexual arousal.
There is also the increasing phenomenon of women who deliberately withhold sex and affection from their partners as a form of power - while this can also happen in reverse, the first situation is much more common in today's society. This is becoming an increasingly common scenario for present day practitioners of couples and sexual counseling. It's not a pretty picture.
There are very few outlets for men in this hellish existence who do not go directly to the "nuclear option" of divorce. The most common is to have an extra marital affair which raises the question of whether infidelity should be legalized.