If you’re a regular coffee drinker, chances are you’re well aware that your stomach isn’t always on board with the buzzy beverage. In fact, more than 20% are estimated to experience digestive symptoms of some sort, according to a 2003 study published in the journal Digestive Diseases and Sciences.

What you might not know is that gotta-poop-right-now feeling isn’t the only potential GI side effect. Nausea can also be a common complaint, Tracey Brigman, EdD, MS, RD, a clinical associate professor at the University of Georgia, tells SELF. You know—that queasiness that makes you want to projectile-vomit over everything in sight. Not only can that make it tough to eat (and hurt your energy levels as a result), it can also cause anxiety (that oh-my-God-am-I-going to hurl-in-front-of-everyone feeling) and “impact your ability to complete any tasks you have at work,” Dr. Brigman says. Given the choice, the diarrhea isn’t looking quite so bad, to be honest.

So what is it about coffee that can make you feel nauseous? Here’s why it happens—and what you can do to prevent it so you can keep sipping.

To be clear, nausea after coffee is a possibility, not a sure thing: “Everybody’s different,” Dr. Brigman says, so “it’s really dependent upon the individual.” For people who do experience it, however, one cause is typically to blame: Increased digestive activity.