Recently, our research team at the Center for Sexual Health Promotion at Indiana University completed the largest nationally representative survey of the U.S. population in nearly 20 years. Specifically, we surveyed women and men ages 14 to 94 about their sexual lives as part of the National Survey of Sexual Health and Behavior.

There were many interesting findings that came from the study and that you may have seen highlighted in the media over the past week, anywhere from The New York Times to the Today show to The Colbert Report. Over the next few weeks, I'll be sharing my thoughts about some of the most striking findings to come from our research.

We found, for example, that about 30 percent of all women ages 18 to 59 reported some difficulty with pain the last time that they had . This compares to about 5 percent of men who reported difficulty with pain. Why does sex hurt for so many women?

We know that about 10 percent of women experience chronic genital pain, some of whom may be diagnosed with vulvodynia. Other women, however, experience more mild or fleeting pain that comes and goes with sex.

For example, some women find it painful if their partner hits up against their cervix during vaginal intercourse or sex toy play. Others find it painful if they start sex too quickly, without adequate vaginal lubrication or the use of a store-bought lubricant. And sometimes women engage in types of sex that they don't enjoy, or that they know from experience to be painful, if they don't feel like they can say no or if they feel as though they "must" or "should" please their partner at all costs.

I wonder, too, how many women think that sex is "supposed" to hurt. After all, young women often get the message that "sex hurts," and so they go into sex expecting some discomfort or pain and not necessarily telling their partner, healthcare provider, or even their best friends that it hurts.

There's some level of "sucking up the pain" that women go through. Men may take physical hits on the sports field more often than women, but our data suggest that women take more hits in the bedroom than men.

What I hope comes from this finding is that more scientists pay to the issue of women's pain during sex. I also hope that more couples pay attention to this issue in their own lives. Here are some things that may help: