Good news: Turns out, research has shown that sex is actually good for you. For example, there's the study that shows that women with active sex lives also tend to live longer lives. There's also research that shows that sex burns calories, relieves stress and helps you sleep better, WebMD reports.
But what happens when you're not in the mood to get between the sheets? A number of things could be to blame -- from health problems to your own psyche. Here, experts share 10 of the most common reasons for a lowered libido.