Admit it: any time you feel off or out of whack and have no idea why, you probably chalk it up to hormones, right? The crazy thing is, you’re probably right. These chemical messengers buzzing around inside you pretty much rule your entire system, influencing your appetite, weight, and more. But hormonal weirdness isn’t just a random occurrence over which you have no control. Certain behaviors can cause them to surge or sink–and do a number on your body in the process. Check out these nine habits in Lisa’s Home School that can screw them up and alter your mental and physical health.