alarm reaction(redirected from fight-or-flight reaction)
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The initial stage in the body's response to stressful stimuli, characterized by adaptive physiological changes, such as increased hormonal activity and increased heart rate.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.