In the 1930s, Dr. William Kerr proposed that chronic, low-level hyperventilation could be behind a host of non-specific symptoms in patients suffering from anxiety, where no organic dysfunction could be found. This has sometimes been called the “fat folder syndrome” for the thickness of the patient’s medical file. These patients complained not only of anxiety or panic, but also feelings of air hunger, chest pain, dizziness and faintness, visual disturbances, fatigue, muscle cramps and poor sleep. Many had shuttled from doctor to doctor for years without a definitive diagnosis. Often they were told that the symptoms were all in their head.
Kerr diagnosed the syndrome by having patients intentionally hyperventilate. If this provocation reproduced their symptoms, he attributed their ailments to chronic hyperventilation, with the presumed mechanism being low levels of blood CO2. In the following years the diagnosis became more common, with the diagnostic test remaining basically the same. Many doctors reported that “fat folder” patients could be helped by restoring healthy breathing patterns.
Questioning hyperventilation syndrome
Since Kerr’s day, researchers have questioned many of his assumptions. Some people who were thought to be chronic hyperventilators actually had normal CO2 levels, while others with low levels of CO2 didn’t have symptoms of the syndrome. For some patients who improved with breathing retraining, those benefits were as likely to stem from relaxation as from changes in CO2 levels.
In many patients with hyperventilation syndrome, asthma has been found to be the underlying cause. Others with hyperventilation syndrome are now seen as primarily suffering from anxiety or panic disorders. in other words, hyperventilation is often a side effect, not the root cause.
Kerr’s hyperventilation provocation test is also no longer considered reliable. The most common method for diagnosing dysfunctional breathing nowadays is a questionnaire called the Nijmegen questionnaire.
(Interestingly, the traditional remedy for hyperventilation, breathing into a paper bag—which in theory involves the hyperventilator re-breathing his own CO2-laden exhaled air until blood CO2 levels normalize—has also been abandoned because of its potential danger for people suffering from hypoxia due to undiagnosed lung disease.)
Still, there seems to be some association between dysfunctional breathing, frequent hyperventilation and the maladies attributed to the syndrome by Kerr, including anxiety and panic, even if the causal linkages are not clear.
Symptoms of hyperventilation—chest pains, air hunger, dizziness and so forth—could provoke anxiety, which in turn could lead to hyperventilation. I would imagine that chest pains—which could arise from strains to the intercostals and other thoracic muscles from habitual upper chest breathing—might feed into anxiety by triggering fears of a heart attack. It’s just hard to know what’s the chicken and what’s the egg.
This brings up the subject of upper chest breathing and hyperventilation syndrome, so let’s look at that now.
Some researchers have noted a connection between hyperventilation syndrome and chronic upper chest breathing without a lateral expansion of the ribcage, or apical breathing.
I am a firm believer that there is no one right way to breathe. Breathing should be adaptable to physiological requirements, as well as postural circumstances and movement needs, which means that having a wide range of available choices in how we breathe is important. Being locked into only one way of breathing is itself dysfunctional.
So this is not meant to suggest that apical breathing is bad. There are circumstances that call for it. But it’s also not hard to see how a habit of keeping your upper chest expanded might lead to a feeling of air hunger that could feed hyperventilation.
Air hunger is the feeling that it’s difficult to get enough air into the lungs. To take a big chest breath you have to forcibly expand the ribcage. It tends to shrink back to its resting shape and size when you exhale, so to keep it chronically inflated takes a lot of work. That leads to a feeling that it’s effortful to breathe, and that you have to work to get enough air in. Not surprising that those who habitually breathe in this way could feel a need to take deeper and deeper breaths to replenish their lungs.
Of course, if your problem is over-breathing in the first place, trying to breathe more deeply will only make it worse, leading to an upward spiral of increasing breathlessness and anxiety.
What does this mean for you?
Regardless of the usefulness of hyperventilation syndrome as a clinical diagnosis, it’s not a good idea to chronically over-breathe, especially if you tend to suffer from anxiety or panic.
The amount of air that moves in and out of your lungs when you are relaxed is actually quite small, only about a half a liter per breath. It doesn’t take a lot of effort to move that much air. Just a small increase in the volume of the lungs, and the air will flow in as a result of the pressure differential you’ve created. You don’t need to strive to pull the air in.
Unfortunately, it’s a common misconception in the yoga world that we don’t breathe enough, and many yoga teachers encourage students in that belief. Yet, as we’ve seen, breathing more than we need to is not healthy, and certainly should not be a habit that we encourage.
In general, let your breathing and natural and unforced. The unconscious part of your brain knows how much you need to breathe, based on your physiological needs. Let it do its job and don’t try to over-ride it by breathing in some way that you think you should.
This is not to suggest that you shouldn’t do specific breathing or pranayama exercises in your yoga practice. In fact, I think they can be helpful if you view them as ways of developing your awareness of how you breathe and increasing your range of available breathing options. I often teach them for those reasons—but not because they’re meant to suggest that we should breathe that way all the time.
In the next part of this series, I’ll look at the breathing technique of kapalabhati as it relates to hyperventilation.
Other posts in this series
Boulding R, et al. Dysfunctional breathing: a review of the literature and proposal for classification. Eur Respir Rev. 25(141):287-94, 2016
Bass C. Hyperventilation syndrome: a chimera? J Psychosom Res. 42(5):421-6, 1997
Gardner WN. The Pathophysiology of Hyperventilation Disorders. Chest. 109:516-534, 1996
Kerr WJ, et al. Physical Phenomena Associated with Anxiety States: The Hyperventilation Syndrome. Cal West Med. 48(1):12-6, 1938
Lum LC. Hyperventilation and anxiety state. J R Soc Med. 74(1):1-4, 1981
Lum LC. Hyperventilation syndromes in medicine and psychiatry: a review. J R Soc Med. 80(4):229-31, 1987
Lum LC. Hyperventilation: the tip and the iceberg. J Psychosom Res. 19(5-6):375-83, 1975
Copyright Joseph Miller