Adrenaline Doesn't Actually Cause the Fight-or-Flight Response, New Study Says

When you're overcome with fear, it's not adrenaline making you want to fight or flee. (Credit: Master1305/Shutterstock) A thrilling high when you're faced with danger, a boost of energy when you're going for an intense run - we tend to associate these rushes with adrenaline, a hormone synonymous with our fight-or-flight response. But it turns out adrenaline might not be what activates our brains' stress reaction after all. In fact, our bones might be doing more work than we originally th