What if you could not experience an orgasm? Wouldn't that put a bit of a damper on your sex life? Well, this is a surprisingly common scenario for many couples as many females are "nonorgasmic" or "inorgasmic." Estimates are in the 10% range.  Of course, this can put a strain on a relationship both for a fella and his honey.
Apparently, the lack of nookie can make everyone involved a little crabby: researchers have noted that a healthy sexual life contributes about 15-20% to the relationship's viability and satisfaction but an unhealthy sex life does the opposite at a rate of about 60-70%.  In other words, lack of sex and quality sex strongly and readily contributes to failed relationships.
So we're going to look at some interesting studies using the Way Back Machine. Back in the 70's, while society was wrestling with free love and, more importantly, the breakup of the Beatles, researchers were frantically looking for solutions to the issues of nonorgasism - is that a word? - and found a few things worth noting. Now nonorgasm can be due to medical conditions, medications and childhood abuse.  However, as it turns out, there can physical reasons as well which will be discussed below.
For example, one study put 8 nonorgasmic women into a fairly involved program with the ambitious goal of getting them to the point where they could orgasm, especially with their spouse and thus achieve a more satisfactory sex life for all. They actually achieved their goal - all 8 women become orgasmic - and presumably lived happily ever after. (Follow up work six months later actually showed that all women stayed orgasmic.) However, if you read the details of the study, the experiences of two of the women is particularly important. These two women had to spend 45 minutes daily masturbating with a virbrator for three weeks before they could achieve an orgasm and had to practice Kegels while they were at it as well!
NOTE: Kegels are excellent for women for many reasons, but subsequent research has not verified their usefulness in overcoming the ability to achieve an orgasm.
For these two women, orgasm was something had to be developed and was a process requiring considerable patience and effort. By all accounts, it appeared that these women did not have a psychological issue, but rather that a physiological one: their vascular, capillary and nervous system simply could not support an orgasm. The researchers speculated that these women had to develop these physiological systems through weeks of stimulation and pointed out that other studies indicated that a lack of "sufficient vascularity" could be the underlying issue. This is verified by the fact that females can become nonorgasmic after the ravages on veins and arteries of diabetes.  Yes, diabetes can produce similar problems in males.
A similar study was done a few years later on 3 nonorgasmic women and documented that it took 3, 4 and 6 weeks of regular masturbation for these women to achieve an orgasm.  The old adage "if at first you don't succeed..." really applies here, eh?
Is this possible? Well, certainly, and there is an analagous situation in men. Men, generally in middle and senior age, may experience a lack of morning erections and/or sexual activity. This leads to atrophy of receptors, musculature and "vascularity" in a sense as well. These men find that they need to literally practice ejaculating for a time and "get back into shape".
The good news is that subsequent research has verified that, generally, nonorgasmic women can become orgasmic through proper strategies. Masters and Johnson, for example, found an 83% and 60% success rate just a few years later. 
2) Archives of Sexual Behavior, 1972, 2(2), "The Role of Masturbation in the Treatment of Sexual Dysfunction"
3) Archives of Sexual Behavior, 1976, 5(3), "Group Therapy for Nonorgasmic Women: Two Age Levels"
4) SEXUALITY AND DISABILITY, 6(2):83-92, "Diabetes mellitus and female sexuality"
5) Handbook of Clinical Family Therapy, Chap. 18, "Couple Sex Therapy: Assessment, Treatment and Relapse Prevention", p. 464.
6) Archives of Sexual Behavior, 1974, 3(4), "Directed Masturbation and the Treatment of Primary Sexual Dysfunction"