The fight or flight response serves an evolutionary purpose. In the face of mortal danger, a surge of stress hormones gives us the energy to fight against threats—or get the heck away. Today, we still have that flood of stress hormones, but when “danger” is a bad day at work, you can’t very well punch your boss in the face or run out of a meeting, can you? In absence of this release, the buildup of cortisol ends up activating your sebaceous (oil) glands and causing inflammation, leading to a breakout.

READ MORE: The Stress-Acne Connection, Explained