There is a better way to breathe while you wear a mask. It's best to breathe in and out through your nose. Many people breathe through their mouth, without even thinking. However, breathing through your mouth tricks your brain into thinking the body needs to engage the "fight-or-flight" response. This could be what is causing some people to feel uncomfortable or anxious. When we breath through our nose, your brain engages the parasympathetic nervous system, or the part of the body that calms us down.