Nervousness is not just a state of mind - for many people feeling nervous is accompanied by all sorts of physical sensations too. Clammy hands, a racing heart and the swooping sensation in the gut commonly known as ‘butterflies in the stomach’ are all normal and natural bodily responses when you’re worried about something.
But why should thinking about an upcoming presentation, sporting event or even a date make us feel this way?
Well, it’s all to do with our autonomic nervous system. The autonomic nervous system is the system in the body responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes.
The autonomic nervous system has two components, the sympathetic nervous system and the parasympathetic nervous system.
“The sympathetic nervous system triggers the fight-or-flight response, providing the body with a burst of energy so that it can respond to perceived dangers. The parasympathetic nervous system promotes the rest-and-digest response that calms the body down after the danger has passed.” (Harvard Medical School)
Experiencing ‘butterflies in the stomach’ is one of the things that happens when the body swaps from resting-and-digesting to the fight-or-flight response. When faced with danger, the body releases adrenaline which increases your heart rate, releases glucose from the liver, and moves blood away from the gut towards the muscles in your arms and legs to prepare you to either face the danger or run away.
It’s the movement of blood from the gut to the muscles in the arms and legs which creates the swooping sensation. As digestion slows, the blood vessels in this area restrict which reduces blood flow. The stomach senses this shortage of blood and oxygen and uses its own sensory nerves to remind us that it still needs to do its job.
Managing this fight-or-flight response is increasingly relevant in the modern world where neither fighting or running away from stresses such as a big upcoming meeting or traffic delays are realistic options. Regularly experiencing ‘butterflies’ if you’re worried about your work/life balance isn’t enjoyable.
But either way, the sensation is here to stay. We’re not sure who coined the term ‘butterflies’ though.