Stress Management Effects on Health All About Catecholamines in the Stress Response Fight or Flight Chemical Messengers By Elizabeth Scott, PhD Elizabeth Scott, PhD Twitter Elizabeth Scott, PhD is an author, workshop leader, educator, and award-winning blogger on stress management, positive psychology, relationships, and emotional wellbeing. Learn about our editorial process Updated on July 02, 2021 Medically reviewed Verywell Mind articles are reviewed by board-certified physicians and mental healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Steven Gans, MD Medically reviewed by Steven Gans, MD Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital. Learn about our Medical Review Board Print Ismailciydem / Getty Images Catecholamines are an important part of the body's stress response, which can be vital in a fight-or-flight response to a perceived threat. They are produced in the adrenal glands, the brainstem, and the brain. In the brain they act as neurotransmitters. In the blood they circulate and act as hormones and are broken down after just a few minutes. They are then excreted in the urine. What Are Catecholamines? Catecholamines include neurotransmitters such as dopamine, epinephrine (adrenaline) and norepinephrine (noradrenaline), which are released during the body's stress response. The adrenaline rush you have probably felt when scared is the result of catecholamines. Simple Explanation They also activate an emotional response in the amygdala of the brain, such as fear of the threat. At the same time, they have effects on attention and other cognitive functions, and can lead to increased aversive long-term memories. You are ready to fight or flee and you are more likely to remember the threat to react to it in the future. If activated for too long, catecholamines can produce negative health effects. To counteract these negative effects, it's important to learn to return your body to its prestressed state before the negative effects of prolonged stress can be seen. Technical Explanation As the stress response is triggered and the body's sympathetic nervous system (SNS) is activated, the adrenal glands release stress hormones like cortisol, while the sympathetic-adrenomedullary axis (SAM) is also triggered to release catecholamines. These circulate through the bloodstream and the brain. They act on neuroreceptor sites to create changes in the body to mobilize energy. This is part of "fight or flight," preparing your body to take action. The immediate effects of catecholamines include: Constricting the blood vessels in the skinIncreasing glucose in your bloodstreamIncreasing your cardiac outputMaking you feel excitedOpening up your lungsRetaining sodiumSending more blood flow to your skeletal musclesSlowing down the intestines Your heart is beating faster and directing the flow to your muscles so you'll be able to run or fight. By reducing flow to your skin, there may be less bleeding in case of an injury. You breathe faster and take in more oxygen. Prolonged exposure to catecholamines can create negative psychological and physical outcomes. Prolonged release of catecholamines can reduce the effects of certain neurotransmitters that affect mood, creating a negative feedback loop between emotions and physiology. These changes can also lead to chronic inflammation of organs and the failure of adaptive systems. This can lead to behavior and quality of life changes, sleep disturbances, metabolic disturbances, and cardiovascular disturbances. A negative feedback loop resolves the stress response, allowing a shift to the body's parasympathetic nervous system (PNS) or the relaxation response, and returns the body to its prestressed state when the perceived threat is gone. Relaxation Response for Reversing Stress 4 Sources Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Henckens MJ, Hermans EJ, Pu Z, Joëls M, Fernández G. Stressed memories: how acute stress affects memory formation in humans. Journal of Neuroscience. 2009 Aug 12;29(32):10111-9. Romero ML, Butler LK. Endocrinology of stress. International Journal of Comparative Psychology. 2007 Dec 31;20(2). Goldstein DS. Catecholamines and stress. Endocrine regulations. 2003 Jun;37(2):69-80. Chrousos GP. Organization and Integration of the Endocrine System. Sleep Med Clin. 2007;2(2):125-145. doi:10.1016/j.jsmc.2007.04.004 Additional Reading American Psychological Association. Stress effects on the body. November 2018. Ranabir S, Reetu K. Stress and hormones. Indian J Endocrinol Metab. 2011;15(1):18-22. doi:10.4103/2230-8210.77573 Sherman DK, Bunyan DP, Creswell JD, Jaremka LM. Psychological vulnerability and stress: the effects of self-affirmation on sympathetic nervous system responses to naturalistic stressors. Health Psychol. 2009;28(5):554-62. doi:10.1037/a0014663 By Elizabeth Scott, PhD Elizabeth Scott, PhD is an author, workshop leader, educator, and award-winning blogger on stress management, positive psychology, relationships, and emotional wellbeing. See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? 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