If you're a woman, this probably sounds familiar. One week out of every month, you find yourself crying more than usual. You have to refrain from snapping at your co-workers. You constantly crave chocolate.
Experts tell women these are just side effects of premenstrual syndrome, or PMS. But if you find yourself in a serious emotional funk that goes so far as to disrupt your work and relationships, you may have PMS's debilitating cousin, premenstrual dysphoric disorder (PMDD). And if the blues continue even after your period, they could be a sign of depression or bipolar disorder.
More from Health.com: 10 ways to get rid of PMS