Nervous SystemStressTrauma

The Physiological Sigh

The Reset Button for Anxiety

Share on Facebook Share on Twitter Share on E-mail
Reading Time: 4 minutes

If you’re looking for instant relief and an “easy button” for turning off anxiety and upset, you’re going to want to learn the physiological sigh. This is a breathing pattern you already know and do when you’re upset and crying and your body is looking to calm down. Now, you can do it purposefully and get the same results. 

Fight or Flight Response

When we enter into fight-or-flight in response to a real or perceived danger, stress hormones flood our body and our sympathetic nervous system revs up.

Welcome to survival mode! Our heart races, our breathing is shallow and fast, digestion slows down, and we feel. agitated, reactive, clammy, scared, sick.

Fortunately, there are science-backed techniques we can use to override fight- or-flight and promote a sense of calm within the body. Breathwork is especially powerful when it comes to modulating the stress response. Why?

Well, unlike other bodily systems—like, say, digestion or cardiovascular activity—we can directly and consciously control that rate and “depth” of our respiration.


When we take a deep breath in, our lungs expand and our diaphragm moves down, creating more space in our chest. This causes our heart to enlarge slightly, which slows down the flow of blood through it. 

Special neurons in our heart detect this change and send a signal to our brain, telling it to speed up our heart rate.

On the other hand, when we exhale, our chest cavity and heart shrink. The same neurons in our heart then signal to our brain that there has been an increase in the rate of blood flow. In response, parasympathetic neurons in our brain stem tell our heart to slow down.

So if you want to tell your body to calm down, take slow, deep breaths where your exhale is longer than your inhale. Remember, inhaling speeds up your heart rate, while exhaling slows it down. That’s why a longer exhale can promote a sense of calm. 

By regulating your breath, you can also regulate your heart activity, activate the vagus nerve, and trigger your body’s natural calming response.

The physiological sigh taps into this breath-heart mechanism and takes it one step further.

The Physiological Sigh

First discovered in the 1930s, the Physiological Sigh has since been researched by Jack Feldman at UCLA and Mark Krasnow at Stanford, among others.

You’ve most definitely both witnessed and experienced the physiological sigh before. Think back to anytime you’ve had a crying fit. As the crying either starts to crescendo or starts to end you start to sniffle a little bit. 

This looks like a few rapid inhales through your nose, or sniffs, then an exhale through your mouth: sniff, sniff, sigh…sniff, sniff, sigh. 

It’s automatic, and you have no choice in doing it.

This is the physiological sigh in action!

The physiological sigh also occurs right before animals, that includes us, are about to fall asleep

Why? What’s going on here?

The Science Behind Nature’s Soothing Breath

Our lungs are covered with millions of tiny air sacs called alveoli. These alveoli can collapse over time, especially when we breathe quickly or shallowly, like when we’re stressed or during certain stages of our sleep.

When the alveoli collapse, carbon dioxide builds up in our bloodstream, making us feel more agitated and jittery.

The double inhale of the physiological sigh helps to open up these tiny sacs, allowing for the exchange of oxygen and carbon dioxide, and getting rid of high levels of carbon dioxide. This brings us back to a state of calm.

In summary, the physiological sigh is a powerful way to regulate our body. It slows down our elevated heart rate, which is a common sign of stress, and removes stress-inducing carbon dioxide.

According to Dr. Andrew Huberman, a neuroscientist at Stanford, recent studies suggest that the physiological sigh is the quickest natural method for us to eliminate the stress response in our body.

Trying to tell yourself to calm down when you’re in fight or flight mode won’t help. The rational part of your brain, the prefrontal cortex, isn’t functioning properly because the emotional limbic brain has taken over. This part of the brain is responsible for our survival instincts.

Using techniques that involve thinking and reasoning won’t be effective. Instead, you need a different approach, like the physiological sigh, which uses your body to signal to your brain that you’re safe and helps convince it of that.

Once you establish a sense of safety, you can respond to situations with careful thought instead of reacting impulsively. The power is now back in your hands. You’ll be able to have more control over how you choose to respond.

Isn’t that amazing? You’ve got this incredible innate power within you that can bring about immediate transformation. It’s like having a superpower that’s always with you.

So the next time you’re in the grip of a stress response and need a quick-acting

tool to calm your body, give the physiological sigh a try. 

How to do the Physiological Sigh

  • Inhale through your nose, drawing air in quickly.
  • Before you get to the “top” of your breath—before your lungs are full—inhale again.
  • As you inhale, make sure your rib cage is expanding out. The pattern should be quick, as if you were taking “sniffs” of air.
  • Hold at the top for a fraction of a second, then expel all of the air out through your mouth.
  • Your exhalation should be longer and slower than your double inhalations.
  • Repeat this cycle 3 to 4 times.

Congratulations! You’ve completed the physiological sigh, a powerful exercise that activates your body’s natural calming response. 

How do you feel?

If you’re ready for more soothing exercises, check out the Your Daily™ app, filled with a library of free nervous system centric exercises, just like this one.

Share on Facebook Share on Twitter Share on E-mail