What Happens During the Fight-or-Flight Response. In response to acute stress, the body's sympathetic nervous system is activated due to the ...SkiptocontentHowtheFightorFlightResponseWorksWilliamHeckman2019-08-21T14:15:21-05:00IllustrationbyJoshuaSeong.©Verywell,2018. Thefight-or-flightresponse,alsoknownastheacutestressresponse,referstoaphysiologicalreactionthatoccursinthepresenceofsomethingthatisterrifying,eithermentallyorphysically.Theresponseistriggeredbythereleaseofhormonesthatprepareyourbodytoeitherstayanddealwithathreatortorunawaytosafety.1Theterm‘fight-or-flight’representsthechoicesthatourancientancestorshadwhenfacedwithdangerintheirenvironment.Theycouldeitherfightorflee.Ineithercase,thephysiologicalandpsychologicalresponsetostresspreparesthebodytoreacttothedanger.Thefight-or-flightresponsewasfirstdescribedinthe1920sbyAmericanphysiologistWalterCannon.Cannonrealizedthatachainofrapidlyoccurringreactionsinsidethebodyhelpedtomobilizethebody’sresourcestodealwiththreateningcircumstances.Todaythefight-or-flightresponseisrecognizedaspartofthefirststageofHansSelye’sgeneraladaptationsyndrome,atheorydescribingthestressresponse.1WhatHappensDuringtheFight-or-FlightResponseInresponseto acutestress,thebody’ssympatheticnervoussystemisactivatedduetothesuddenreleaseofhormones.Thesympatheticnervoussystemsstimulate the adrenalglands triggeringthereleaseofcatecholamines,whichincludeadrenalineandnoradrenaline.Thisresultsinanincreaseinheartrate,bloodpressure,andbreathingrate.2Afterthethreatisgone,ittakesbetween20to60minutesforthebodytoreturntoitspre-arousallevels.Youcanprobablythinkofatimewhenyouexperiencedthefight-or-flightresponse.Inthefaceofsomethingfrightening,yourheartbeatquickened,youbeginbreathingfaster,andyourentirebodybecomestenseandreadytotakeaction.Thefight-or-flightresponsecanhappeninthefaceofanimminentphysicaldanger(suchasencounteringagrowlingdogduringyourmorningjog)orasaresultofamorepsychologicalthreat(suchaspreparingtogiveabigpresentation atschoolorwork).Someoftheph