Panic attacks and CO2


Senior Member
This study points out how increased blood levels of CO2 can be at the basis of the 'flight or fight response' in panic attacks.

I have often thought that CFS sufferers are mainly 'shallow breathers' due to our lower activity levels. This can increase CO2 blood levels and could explain some of the 'flight and fight' symptoms, of which the panic attack is the ultimate response.

We take deep breaths as a natural response to panic attacks and this lowers CO2 levels and lowers the symptoms.

Regular breathing exercises every day I find helps to keep CO2 levels lower throughout the day and this cuts down on the number of 'flight and fight' symptoms.

Study sheds light on brain's fear processing center

Breathing carbon dioxide can trigger panic attacks, but the biological reason for this effect has not been understood. A new study by University of Iowa researchers shows that carbon dioxide increases brain acidity, which in turn activates a brain protein that plays an important role in fear and anxiety behavior.

The study, published in the Nov. 25 issue of the journal Cell, offers new possibilities for understanding the biological basis of panic and anxiety disorders in general and may suggest new approaches for treating these conditions.

The researchers focused on a brain protein known as acid-sensing ion channel 1a (ASIC1a). This protein is abundant in the amygdala -- the region deep in the brain that processes fear signals and directs fear behavior. The UI team previously found that blocking or removing ASIC1a reduces innate fear and alters fear memory in mice.

"As long ago as 1918, scientists learned that carbon dioxide triggers abnormal responses in patients with anxiety disorders, but our study provides the first molecular evidence for a mechanism that explains how carbon dioxide can trigger fear and anxiety," said John Wemmie, M.D., Ph.D., associate professor of psychiatry and neurosurgery at the UI Carver College of Medicine and a staff physician and researcher at the Iowa City Veterans Affairs Medical Center. "The findings are a foundation for saying that ASIC proteins in the amygdala might play a key role in sensitivity to carbon dioxide."

In addition to helping explain why breathing carbon dioxide can trigger panic attacks, the study also suggests a new role for the amygdala as a sensor that can detect certain fear signals for itself.

"This is a new finding that the amygdala, which is considered the brain's computer processor for fear, can also function as a sensor for detecting chemical signals -- carbon dioxide and acidity (low pH) -- that are known to trigger panic attacks in susceptible individuals," Wemmie said.

Carbon dioxide inhalation can be deadly at high doses. The study suggests that evolution may have provided humans with a vital ability to detect and respond rapidly to carbon dioxide by placing within the same brain region the ability to detect the threat posed by carbon dioxide and the ability to initiate a "fight or flight" response.

The new study shows that inhaled carbon dioxide increases brain acidity and evokes fear behavior in mice by activating ASIC1a in the amygdala. Fear memory is also enhanced when carbon dioxide activates the protein.

Conversely, the study team, including first author Adam Ziemann, M.D., Ph.D., found that making brain tissue less acidic (raising brain pH) blunted fear behavior produced by carbon dioxide and reduced learned fear.

"It's been suggested that controlling breathing with breath exercises could have anti-anxiety effects," Wemmie said. "Our results make me wonder if some of those breath exercises to control fear and anxiety might be acting by inhibiting the ASIC channels in the amygdala by raising the pH."

Wemmie and his colleagues are now investigating whether ASIC1a abnormalities contribute to panic and anxiety disorder in people or to carbon dioxide sensitivity in patients with panic disorder.

If ASIC1a plays the same role in people as the studies suggest it does in mice, then drugs that target ASIC channels or strategies that alter brain acidity could hold promise for treating a wide range of panic and anxiety disorders.

Alice Band

PWME - ME by Ramsay
Hi Liverock,

I've had my breathing tested and there was no sig of shallow breathing or CO2 problems. The tests involved being connected to a machine that tests the breath and then blood tests.

I also don't have panic attacks. Might be a ME thing or even a me thing. No idea. as I'm an old timer survivor from an acute viral outbreak.

Also fit the criteria for CFS CDC and Canadian.

Just wanted to say that not all people with these conditions have breathing problems or are shallow breathers.

Not meaning anything derogatory about people with CFS who have this symptom. We are all different.


Senior Member
Gold Coast Australia
shallow breathing

I am a shallow breather.....adrenalin running all the time as a result. did Buteyko breathing for a good while and it helped a lot. Putting tape across my mouth at night was good also to train me. Was inhaling 23 breaths a 12. I think shallow breathing is a big issue with CFS and many people dont realize it.....I did not till it was pointed out to me.


Senior Member
The breathless involved in CFS can be easily explained. Excessive sympathetic overactivity results in an increase in chemoreceptor sensitivity and a decrease in baroreflex sensitivity. And the result is postural hypocapnia and cerebral vasoconstriction, POTS and anxiety.


And lowered oxygen saturation.

And weak diaphram muscles (due to very low ATP) leading to systemic muscle weakness.

And chronic mast cell activation.

And changes in pulmonary circulation.



Senior Member
Front Range Colorado
i have been doing buteyko breathing exercises again in this severe crash i am in. while mouth taping is helping greatly with hyperventilation at night i am starti g to think that i have been oxygen depriving myself with the shallow reduced breathing and pauses at the end of exhalation that i have been doing. perhaps i am reduci g my breathing too much b/c i am misunderstanding buteyko or perhaps it is unhelpful.

anyone else find that deep relaxed breathing is better than or a necessary adjunct to buteyko?


Senior Member
I just want to add to my comment, I have tried it and found it useful for a while in 2009. But I have been through some changes since then and now I feel a sense of panic when I get down into the trace state in a meditation or deep into reduced breathing with buteyko. I think this probably has something to do with potassium and sodium and perhaps magnesium. Its not a perfect relationship, but I tend to get palpitations when I have low O2 concentrations as measured by a pulse oximeter, these tend to be resolved by taking salt and potassium, my %O2 also increases following a MgSO4 footbath but it happens more slowly. I seem to have some issues with using/retaining potassium probably adrenal issues (the adrenal glands control the concentrations of these minerals) but it could also be the pituitary etc etc. The thing is that these things lead to changes in the pH of the blood which feeds into oxygenation and CO2 concentration, and buteyko changes the CO2 concentration and my sense of panic is probably related to this whole mess. I know that Constantine Buteyko was a major fan of having a lot of salt, in the classes I took nutrition was as important as the exercises and it might just be that I am too far away from health to be able to do it at the moment.

I last made a good attempt at it in december and January using the site I linked to, I found it to be particularly good at explaining the concepts and I think that it is worth trying; but I suggest that you remember to listen to your body too.

I hope to try it again when I get the electrolytes under control.