<Table> <Tr> <Td> </Td> <Td> Look up have butterflies in one's stomach in Wiktionary, the free dictionary . </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> Look up have butterflies in one's stomach in Wiktionary, the free dictionary . </Td> </Tr> <P> Butterflies in the stomach is the physical sensation in humans of a "fluttery" feeling in the stomach, caused by a reduction of blood flow to the organ . This is as a result of the release of adrenaline in the fight - or - flight response, which causes increased heart rate and blood pressure, consequently sending more blood to the muscles . </P> <P> It can be a symptom of social anxiety disorder . The symptom of this phenomenon is usually experienced prior to attempting to partake in something critical . </P>

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