Almost everyone has experienced that fluttery feeling in the stomach before a big presentation or a first date. Most of us know this feeling by the un-scientific name “butterflies,” but it turns out there are some scientific reasons behind the sensation. The digestive system is closely linked to a person’s thoughts and emotions, so those pre-presentation jitters can quickly turn into stomach acrobatics.
Butterflies to the Rescue — Why It Matters
Stomach butterflies are associated with the body’s fight-or-flight response. When the brain perceives a potential threat to survival, it increases alertness by raising heart rate, blood pressure, and breathing rate. At the same time, the nervous system stimulates the adrenal glands, which release hormones including adrenaline and cortisol that can turn the body into a tense, sweaty mess. Muscle tension (especially in the stomach) helps keep us alert; perspiration helps cool the body down. The smooth stomach muscles are also extra-sensitive during the fight-or-flight response, and the added sensitivity may be partly to blame for that fluttery sensation. Some researchers refer to the stomach as the “second brain,” based on findings that the gut contains 100 million neurons linking it to the brain, known as the brain-gut axisMicrobes and the gut-brain axis. Bercik, P., Collins, S.M., Verdu, E.F. Farcombe Family Digestive Health Research Institute, McMaster University, Hamilton, Canada. Neurogastroenterology and Motility, 2012 May;24(5):405-13. doi: 10.1111/j.1365-2982.2012.01906.x.Enteric dopaminergic neurons: definition, developmental lineage, and effects of extrinsic denervation. Li, Z.S., Pham, T.D., Tamir, H., et al. Department of Anatomy and Cell Biology, Columbia University, College of Physicians and Surgeons, New York, New York. Journal of Neuroscience 2004;24(6):1330-9.The enteric nervous system and neurogastroenterology. Furness, J.B. Department of Anatomy and Neuroscience, University of Melbourne, Grattan Street, Parkville, Australia. National Review of Gastroenterology and Hepatology, 2012 Mar 6;9(5):286-94.. So when we feel nervous before a stage debut, the brain communicates that anxiety to the gut, sometimes causing a case of the butterflies. But to fully understand the reasons behind the butterflies, we may have to look back hundreds of thousands of years.
I’ve Got a (Gut) Feeling — The Answer/Debate
The fight-or-flight reaction may be part of an evolutionary response. Back when people had to be prepared to run from attacking lions (or other prehistoric beasts), an increased heart rate and tense muscles might have helped them make a quick escapeAnxiety: an evolutionary approach. Bateson, M., Brilot, B., Nettle, D. Reader in Ethology, Newcastle University, England. Canadian Journal of Psychiatry, 2011 Dec;56(12):707-15.. So even though a job interview isn’t necessarily a life-threatening situation, the body may deal with the stress the same way it handled the lion chaseAnxiety: an evolutionary approach. Bateson, M., Brilot, B., Nettle, D. Reader in Ethology, Newcastle University, England. Canadian Journal of Psychiatry, 2011 Dec;56(12):707-15.. And ever want to throw up before that interview? Sometimes those butterflies can turn into nausea, since the adrenaline rush can temporarily stop digestion. Blood leaves the places where it’s not needed, like the stomach, and flows to body parts where it might be necessary, like the muscles, so cavemen’s legs could spring into action while they ran for their livesStress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options. Konturek, P.C., Brzozowski, T., Konturek, S.J. Department of Medicine, Thuringia Clinic Saalfeld, Teaching Hospital of the University Jena, Germany. Journal of Physiology and Pharmacology, 2011 Dec;62(6):591-9.. (Today those legs may not be running from a stampede, but they may need some help staying upright when that hottie from next door walks by.) Butterflies are usually harmless, but if these fight-or-flight feelings interfere with daily life, it might be time to speak to a doctor. A frequent nervous stomach may be a sign of an anxiety disorder or even a gastrointestinal issueIrritable bowel syndrome–irritable bowel or irritable mind? Marlicz, W., Zawada, I., Starzyńska, T. Pomeranian Medical University of Szczecin, Poland, Department of Gastroenterology. Polish Merkuriusz Medical, 2012 Jan;32(187):64-9.Role of stress in functional gastrointestinal disorders. Evidence for stress-induced alterations in gastrointestinal motility and sensitivity. Mönnikes, H., Tebbe, J.J., Hildebrandt, M., et al. Department of Medicine, Division of Hepatology and Gastroenterology, Universitätsklinikum Charité, Campus Virchow-Klinikum, Humboldt-Universität zu Berlin, Berlin, Germany. Digestive Disease, 2001;19(3):201-11.Neurotic butterflies in my stomach: the role of anxiety, anxiety sensitivity and depression in functional gastrointestinal disorders. Norton, G.R., Norton, P.J., Asmundson, G.J., et al. Department of Psychology, University of Winnipeg, Manitoba, Canada. Jouranl of Psychosomatic Research,1999 Sep;47(3):233-40.. One way to deal with butterflies is to convince the body that it’s not in actual physical danger. Take a deep breath and relax. Unless you’re eyeing a position as a flame-thrower in the circus, job interviews aren’t really that dangerous, right?
Butterflies are part of the body’s fight-or-flight response when there’s a threat to survival.
The stomach muscles get extra-sensitive during the fight-or-flight response, and that’s partially what causes the butterflies.
Neurons along the brain-gut axis let the stomach know when we’re freaking out about something .
Butterflies and the fight-or-flight response may serve an evolutionary function.
There’s nothing wrong with feeling fluttery once in a while, but if the feeling persists, it’s best to seek medical help.