We can't help it. We're humans, and we get stressed. But the way we deal with it could either help us stay healthy this cold season, or — as this new Ted Ed video explains — leave us vulnerable to some nasty bugs. As we've written before, stress isn't necessarily a bad thing, as long as you're able to calm down relatively quickly. Our stress responses evolved as a part of the fight-or-flight instinct, meaning they're actually supposed to be helpful. But when stress or anxiety is chronic, that constant heightened state is pretty hard on our bodies. For one thing, when your brain senses you're stressed, it sends out a kind of emergency alarm to other systems in your body. And one of those — your immune system — can really take a beating when this happens. The video explains that when you first get anxious, your immune system steps up to the plate to keep out potential intruders and help you feel better if you do get sick. But as time goes on, that higher level of immune activity is more and more difficult to sustain. And eventually, your poor immune system becomes exhausted. That leaves you more vulnerable to whatever illness or infection comes along. And it doesn't help that being sick and having to take time off can stress us out even more. So while it's unreasonable to think you can keep stress away, always and forever, it's a good idea to begin to notice yourself getting stressed and to find productive ways of processing those signals. (May we suggest some beginner meditation?) That way, those anxious feelings will take their cue to do their job — and then leave you alone (and healthy).