is the expression butterflies in your stomach reality

Question: is the expression butterflies in your stomach reality
- Keywords:
  butterfly,
  human body,
  stomach
Asked by 873heaq27 to Kevin on 8 Mar 2019.
- Kevin OBrien answered on 8 Mar 2019:
  
  I hope not, or else I’ve had a lot of butterflies in my stomach, particularly ahead of exams and interviews.

Question: is the expression butterflies in your stomach reality