Why We Sigh

Wishful

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During certain phases of my ME, I notice that I sigh a lot. I did wonder why, so a bit of googling turned up a PopSci article: https://www.popsci.com/sigh-reason-study/

"That stretch is critical to keep lungs working properly. "When alveoli collapse, they compromise the ability of the lung to exchange oxygen and carbon dioxide," Jack Feldman, a neurobiologist at UCLA and one of the study authors said in a press release. "The only way to pop them open again is to sigh, which brings in twice the volume of a normal breath. If you don't sigh, your lungs will fail over time.""

"The researchers decided to look in the brain’s breathing center in the brainstem. They analyzed the genes in those cells and found that a few hundred of them generate one of two chemicals that allow them to communicate with the "preBötzinger Complex," a bundle of a few thousand neurons known to control the rate and rhythm of respiration."

From my hypothesis, ME subtly alters the function of some brain cells. If it affects this specific clump of cells, it can alter our rate of sighing. I expect that even a slight alteration of neuron trigger thresholds or signal transmission could have a noticeable effect on sigh rate.

For PWME who have breathing issues, this might be part of the answer. In a similar fashion, these subtle alterations could affect gut function, urination frequency, temperature regulation, and many of the other symptoms PWME suffer.


*sigh*
 

Pyrrhus

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From my hypothesis, ME subtly alters the function of some brain cells. If it affects this specific clump of cells, it can alter our rate of sighing. I expect that even a slight alteration of neuron trigger thresholds or signal transmission could have a noticeable effect on sigh rate.
The brainstem again. That makes sense.

For PWME who have breathing issues, this might be part of the answer. In a similar fashion, these subtle alterations could affect gut function, urination frequency, temperature regulation, and many of the other symptoms PWME suffer.
Yup. These autonomic actions are also partly controlled by the brainstem.
 

Wolfcub

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In a similar fashion, these subtle alterations could affect gut function, urination frequency, temperature regulation, and many of the other symptoms PWME suffer.
I agree. I came to that conclusion myself, concerning my own issues, as I get problems with all these things. Something is going on in the brainstem (it also affects my trigeminal nerve and leads to an array of symptoms related to that.) But I sense it's all coming from some weirdness going on in the brainstem.

And I found I was sighing a lot too. Not for emotionally generated reasons.
 

Blue Jay

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I have noticed that I have periods of sighing and had sighed just before and during reading through this thread. Interesting.
 

Wishful

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I think I sigh just as much while hiking up a slope (breathing more heavily) as I do while sitting and reading, so I don't think it's a matter of inadequate depth of breath. It makes more sense that the controlling braincells are just firing the 'sigh' signal more often than normal.

I doubt that anyone is actually going to do the testing required, but I think that if they did measure lung characteristics and monitored the respiratory centre, they'd find the lungs normal and an abnormal rate of activity in the centre.
 

lauluce

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Wishful

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Yep, that’s why I don’t think it’s sighing per se, it’s needing to take a much deeper breath of oxygen
Does the rate change with activity level? If it was simply a need for oxygen, it should occur less often if you're already breathing more heavily. My rate of sighing doesn't seem to change with activity level. That's why I think it's just an abnormally increased rate of triggering the 'sigh reflex'.

It's really hard to honestly self-judge mental states, but it seems that I feel some sort of change of mental state when I sigh (momentary depression?). Of course, that doesn't say anything about cause or effect, since forcing a smile on your face can make you feel happier. Just musing here...
 

Pyrrhus

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Does the rate change with activity level? If it was simply a need for oxygen, it should occur less often if you're already breathing more heavily.
If there is "chronotropic incompetence", as previous work has suggested, then the heart might fail to increase its rate of beating enough to keep up with an increase in activity.

I wonder if a similar thing might happen with the lungs?
 

leokitten

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Does the rate change with activity level? If it was simply a need for oxygen, it should occur less often if you're already breathing more heavily. My rate of sighing doesn't seem to change with activity level.
Good question, I haven’t been able to significantly increase my physical activity level for a long time so it’s hard to say now as I don’t remember.

I also have ME-caused bradycardia with my resting heart rate in the mid 50s. Pre-illness it was 60-70s. During the first year of illness and the acute post viral syndrome stage where symptoms were the most all over the place I initially had occasional bouts of OI and POTS, but that went away and I never had it since (I’m male too so not common). It’s like ME caused everything to slow down.
 

Wishful

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I wonder if a similar thing might happen with the lungs?
But that would change the rate of sighing with activity level: if the lungs weren't keeping up with muscle demand, you'd sigh more often.

As I see it, the brain has a clump of cells that is a 'sigh reflex'. When the inputs hit a threshold, it triggers a cascade of signals that results in a sigh. There might be several inputs, such as from lung alvioli, and blood CO2, and maybe some negative signals (don't sigh while running). ME might change the threshold or the signal transmission, so that we get a lot more 'false triggers'.

Imagine that your keyboard had a bit of conductive dust under a keyswitch, so that a bit of vibration made it occasionally conduct enough to trigger the electronics. As you type, or even just stare at the screen, it occasionally puts out a 'k'. Tkhat woukld bekannkoyking. ;)
 

Wishful

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I came across a link https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4386588/ that explains that sighing may be important for providing variability in cardiovascular rhythm. Oscillatory systems may need some sort of feedback to prevent them from going out of control. Random or semi-random inputs help keep that working properly. So, it's possible that something is going on with our cardiovascular system that requires more frequent sighing.

Another possibility is that there's something wrong with the neurons responsible for not noticing sighs. We supposedly sigh a dozen or so times per hour without noticing them. There's probably some neural functioning going on to prevent that from being distracting. If that went wrong, we would notice the sighs. At this point, I'm not certain whether I'm sighing more often (or deeper) or whether I'm just noticing them more.
 

Wishful

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More observations of my sighing. Humans supposedly sigh about 15x per hour, or once very 4 minutes. I've been paying attention to my sighs, and I think once every four minutes is about right, so it's not my rate that's abnormal. The question is: is my magnitude abnormally high, or is it just my awareness of them? An experiment for those of you who live with someone: Pay attention to their breathing for a quarter hour or so. Do they sigh noticeably in that time, or are normal '15x per hour sighs' imperceptible?
 

Wishful

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Another observation: My frequent sighing seems to correlate with VitC intake. I've avoided VitC for a couple of weeks, and didn't notice much sighing. Then I took VitC tablets for two days, and the frequent sighing was back. This test followed a previous VitC/sighing observation. It takes a couple of weeks for the effect to fade, so testing is slow, but I will try again. I have no hypothesis for why VitC would cause frequent sighing.

For anyone else who suffers from frequent sighing, maybe try varying VitC intake and seeing whether you notice a correlation.


BTW, I consider frequent sighing much less annoying than bleeding gums. ;)
 

sb4

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When I was at my worst I would have short period's of time, like 30 seconds, where I would have no urge to breathe whatsoever. It was really wierd. I would be breathing normally then suddenly nothing, I'd just sit there and wait for the urge to breathe to come back and it would take a long time, quite bizarre.

Not had this in years now. Wouldn't surprise me if it was in issue in the neurons responsible for breathing / brainstem.
 
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When I was at my worst I would have short period's of time, like 30 seconds, where I would have no urge to breathe whatsoever. It was really wierd. I would be breathing normally then suddenly nothing, I'd just sit there and wait for the urge to breathe to come back and it would take a long time, quite bizarre.
I take breathes and then hold my breathe a bit after- I do this alot.

My husband knows I woke up because: I start holding my breathe. As I read some of this, instead of sighing I noticed i hold my breath a bit and then gasp. wow I'm still doing this- I had stopped noticing it.

wow.
 

Wishful

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Wouldn't surprise me if it was in issue in the neurons responsible for breathing / brainstem.
It's only a few thousand neurons involved, so if you subtly alter the firing rate of a few of those, it seems reasonable to have breathing irregularities. Worn sparkplugs certainly had a noticeable effect on my engine's performance. Too bad we can't just pop the braincase open and replace the worn parts.