Back to school means happy things like reconnecting with friends and catching up on summer gossip. One less fun thing? Going back to waking up early and getting out the door fast. You might be tempted to reach for your favorite caffeinated beverage (extra large, please) to jump-start your day. But do you really know what all that caffeine is doing to you? While a little bit of caffeine is not terrible, your body can become dependent on it. And using too much of it too often can lead to long-term health problems and trouble sleeping. In fact, studies have shown that teens are especially vulnerable to some of the issues associated with caffeine consumption, such as dehydration, anxiety, and (gross-out alert) diarrhea. So before you reach for that soda, latte, or energy drink, read on to find out about the effects of caffeine on your body, mind, and mood.