Insights into Psychology

What Is… The Diving Reflex

The dive reflex: Take advantage of your inner dolphin to slow your heart rate and calm your body

In this series, I dig a little deeper into the meaning of psychology-related terms. This week’s term is the diving reflex. While the reflex itself has nothing to do with psychology, it’s actually still relevant.

The diving reflex is present in all mammals to some extent. It triggers a number of physiological changes that allow us to spend longer periods of time underwater. Does anxiety help prolong your dolphin time? Nope, so the body does what it can to shut that nonsense down.

In humans, including infants, this reflex is triggered when we’re holding our breath and put our face (and specifically our nose) in cold water. Sensory receptors in the face and nose tell the brain what’s going on, and the brain responds by slowing the heart rate by 10-25%, decreasing blood flow to the periphery, and increasing blood flow to the heart and brain.

The diving reflex and mental state

All of this happens as a reflex; there’s no conscious thought required. The parasympathetic nervous system, and specifically the vagus nerve, take care of it for you. If your anxiety is spiking and you’re approaching a panic attack or you’re feeling totally dysregulated, this could be a quick way to settle things down in the body.

The diving reflex is also involved in the dialectical behaviour therapy (DBT) TIPP acronym. The T is for temperature change, which involves sticking your face in a sink full of cold water, setting off the reflex.

Anxiety and hyperventilation

On a vaguely related note, let’s talk breathing and anxiety. While thinking about your breathing in the midst of extreme anxiety or panic may seem about as reasonable as trying to meditate during a riot, there’s actually a good biological reason to get your breathing under control.

When we breathe, we need oxygen coming in and carbon dioxide going out. When you hyperventilate, as often is the case with intense anxiety, you’re blowing out a lot of carbon dioxide. Even though you need to breathe in oxygen, your brain doesn’t decide if you’re breathing properly based on how much oxygen is inside of you; it makes that call based on how much carbon dioxide there is. Part of why your brain cares about carbon dioxide so much is that it can throw off the pH balance in your blood. If you’re blowing off too much carbon dioxide, red flags start flying in your brain, screaming out that you can’t breathe. If you weren’t anxious before, you sure as hell are now.

To counteract this, slow the breathing way down, especially the exhales. Breathing out through pursed lips can slow the speed that you’re releasing CO2. You could also do the old-school breathing into a paper bag trick, which allows you to re-inhale CO2. This may not relieve your anxiety, but it will stop you from shooting yourself in the foot.


Our bodies are truly remarkable things. Sometimes, the things they do automatically can make things worse, but knowing the right tricks can help you take advantage of your automatic responses. Have you experienced either of these effects and found it made a difference in your mental state?

Source: Wikipedia: Dive reflex

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36 thoughts on “What Is… The Diving Reflex”

  1. That’s fascinating!! I love the water trick, and I’m going to try to commit it to memory, because anxiety happens! I’m fascinated by physiological life hacks.

    The breathing stuff is interesting! I’ve always hated being told to focus on my breathing. You’ve actually explained the science behind it, which could reinforce the concepts for me if I’m ever having some sort of anxious meltdown.

    One thing has always confused me. I grew up swimming quite a bit, and I’d go to the bottom of the pool in the deep end and just sit there. (It was about nine feet underwater.) The weird thing is that I never held my breath. Instead, I’d take a few deep breaths and then let them out; and then I’d be ready to go under. But everyone else always references “holding their breath”, so I have no clue if that’s just the vernacular, or if I’m the only person who does that. You have to wonder.

    Very interesting blog post!! You can never have too many tools in the mental illness toolbox!!

    1. I was just looking up the holding the breath thing and it sounds like people aren’t supposed to hold their breath; they’re supposed to exhale in the water. I think that’s what I do, because I recall liking the bubbles from it.

  2. Many years ago I used the paper bag trick for the first time by a doctor, because of my first hyperventilating incident when me and mum thought it was something else.
    It certainly works.

    Since then, I have had some attacks, but no paper bag, but used the cupped hands technique. Which again, that doctor told me about that while I was breathing into the paper bag.

    I have automatically, without thought used pursed lips, without thinking.

      1. Yes, it is.
        It wasn’t until I read the pursed lips part in your post though that I thought, I do that. So that’s how automatic, that is for me.

  3. Great post. Have not heard about this before. The part about breathing during a panic or anxiety attack is true.
    If I have a panic attack while shopping I stop everything I am doing. I close my eyes and focus on my own breathing. I stay that way until my breathing is calm again.

  4. I’m now remembering that if it’s bad I do cold showers. I discovered that on my own but now I know why. I had read somewhere that it forces you to take deeper breaths if it’s cold water on the whole body.

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