A closer look
Experiencing the romantic sensation of butterflies in your stomach is actually just the biological manifestation of your primal fight-or-flight response pulling blood away from your digestive organs. When you see your crush or face an impending threat, your brain aggressively redirects blood flow toward your leg and arm muscles so you can physically fight them or run away in terror. The sudden lack of oxygenated blood in your gastrointestinal tract causes the stomach to temporarily shut down its normal operations, creating that fluttery, nauseous feeling. We have spent centuries romanticizing this intense physical reaction in poetry and literature, but your central nervous system is just preparing your physical vessel to throw a punch or aggressively sprint in the opposite direction
