A Sigh, But Why?
You sigh about twelve times an hour, and most of the time you never notice. We tend to think of a sigh as sadness, relief or exhaustion. It turns out it is also one of the most important breaths you take, and your phone may be quietly taking some of them away.
The short answer. Your body sighs on its own to reopen tiny air sacs in the lungs and reset your breathing. A 2022 study found that reading on a smartphone was linked with fewer sighs than reading on paper. Sighing on purpose and taking real screen breaks are simple ways to give those resets back.
Breath is a behavior
Breathing is one of the most fascinating behaviors controlled by the nervous system. It ranges from the gas exchange essential for life to complex, still unknown brain networks that help modulate almost every human function: metabolic rate, vocalization, emotions, cognition, posture, sleep-wake state, anxiety, panic, focus, stress regulation and beyond.
Why we sigh
A sigh happens spontaneously to reinflate the alveoli, the tiny air sacs in the lungs. Over time some of them partially collapse. A sigh, roughly a double-sized breath, pops them back open to support gas exchange and keep the lungs healthy.
The science of a sigh
Jack Feldman, Mark Krasnow and colleagues mapped the sigh circuit (Li 2016; see also Del Negro 2018). A small group of brainstem neurons releases bombesin-like neuropeptides. These signal to the preBötzinger complex (preBötC), the region that drives each inhale, and turn a normal breath into a sigh. These neurons appear to be the core control circuit for sighing, connected to brain regions that monitor physiological and perhaps emotional states.
The circuit is now mapped, and its role in reopening the alveoli is clear. Researchers are turning to the psychological side: the full neural circuit, how sighing shapes normal breathing, and how it relates to nervous system states. I like to look at breath as a behavior. It is flexible, interconnected and two-way. Your state of being shapes how you breathe, and how you breathe shapes your state of being.
Researchers have also suggested that this pathway could one day lead to medicines for people who sigh excessively, or for people who cannot breathe deeply on their own. To me it raises another question: what role can a daily breathing practice play in building a real-time toolkit for physiological and psychological self-regulation?
Sighs can be learned
A 2020 paper suggests sighs can become learned behaviors through operant learning (Vlemincx 2020). We may learn to sigh more because of the relief a sigh brings in moments that call for physiological or psychological regulation. That opens interesting questions about learned breathing habits, breathing patterns that drift out of balance, and how breath practice could be a simple, noninvasive way to support wellbeing.
What screens do to your sighs
A 2022 study in Scientific Reports found that how we read changes how often we sigh, but not our normal breathing (Honma 2022). People reading on a smartphone sighed less than people reading the same text on paper. They also showed more prefrontal brain activity and understood less of what they read. The researchers point to sustained attention and higher mental load on the small screen as possible reasons. My read is that when you are locked into a phone, your body skips some of the resets it would naturally take.
Simple ways to regulate in real time
- Read long-form on paper or a larger screen when you can.
- Sigh on purpose every few minutes during screen work. Two inhales through the nose, one long exhale through the mouth. My physiological sigh guide walks you through it.
- Take screen breaks outside. Two to three times a day, or every 45 minutes during work hours, step outside and let your eyes go wide into panoramic vision and the natural movement of the world around you.
- Keep a daily breathing practice. A few minutes every day helps reinforce healthy, natural breathing patterns.
Thanks to Dr. Andrew Huberman for the first two of these tools.
Please practice safely. This is education, not medical advice. Never practice breath holds or breathing exercises in or near water, while driving, or anywhere fainting could hurt you. If you have a medical condition, speak with your doctor before starting a new breathing practice.
For a full daily routine, read breathing for nervous system regulation, and see the breathwork guide for the science.
Questions people ask me
Why do we sigh?
Mainly to reinflate the tiny air sacs in the lungs that partially collapse over time. Sighs also show up with emotional shifts like relief, and they seem to help reset breathing.
How often do people sigh?
About every five minutes, roughly twelve times an hour, usually without noticing.
Does looking at your phone change your breathing?
One 2022 study found that reading on a smartphone was linked with fewer sighs than reading on paper, while normal breathing stayed the same.
What is the difference between a sigh and a physiological sigh?
A sigh is the spontaneous double-sized breath your body takes on its own. A physiological sigh is the deliberate version: two inhales through the nose and one long exhale through the mouth, used on purpose to shift your state.
Practice it with me
My free 10-minute guided session walks you through the sigh and a full breathing practice.
References
- Li et al. (2016). The peptidergic control circuit for sighing. Nature. doi.org/10.1038/nature16964
- Del Negro, Funk and Feldman (2018). Breathing matters. Nature Reviews Neuroscience. doi.org/10.1038/s41583-018-0003-6
- Vlemincx and Luminet (2020). Sighs can become learned behaviors via operant learning. Biological Psychology. doi.org/10.1016/j.biopsycho.2020.107850
- Honma et al. (2022). Reading on a smartphone affects sigh generation, brain activity, and comprehension. Scientific Reports. doi.org/10.1038/s41598-022-05605-0
An earlier version of this piece first appeared with Our Breath Collective in February 2022.