Breathing pattern disorder vs autonomic breathlessness: how to tell the difference

If you’ve developed breathlessness after a viral illness, had normal chest X-rays and spirometry, and visited your GP more than twice about it, someone has almost certainly mentioned breathing pattern disorder. It may have been framed gently, as a functional explanation. It may have been accompanied with a referral to physiotherapy. It may have felt like being told the problem is in your head.

Breathing pattern disorder is real. It also gets significantly over-applied to people with post-viral conditions, where breathlessness often has a different and more specific cause. Getting the distinction right matters, because the treatments are different and applying the wrong one wastes time at best and causes harm at worst.

What breathing pattern disorder is

Breathing pattern disorder (BPD) refers to a pattern of dysfunctional breathing that perpetuates breathlessness symptoms. The most common form is chronic hyperventilation: breathing at a rate or depth that keeps carbon dioxide (CO2) levels chronically low, sensitising chemoreceptors and perpetuating the sense of breathlessness even in the absence of physiological oxygen insufficiency.

It’s maintained by a feedback loop. Anxiety or physical symptoms trigger faster breathing, which lowers CO2, which causes symptoms (light-headedness, tingling, chest tightness, breathlessness), which increase anxiety, which increases breathing rate further. Breaking the loop typically involves breathing retraining — slowing the breath rate, nasal breathing, diaphragmatic technique.

BPD is common in the general population, more common in women, and frequently coexists with anxiety disorders. It’s also common in long COVID — but so is genuine autonomic breathlessness, and distinguishing between them requires more than noting that the lung function tests are normal.

What autonomic breathlessness is

In post-viral dysautonomia and POTS, breathlessness is often positional and exertional in a specific way: it’s worst on standing, worsens with mild activity, and improves significantly when lying down. The mechanism is not pulmonary — the lungs are working normally — but cardiovascular and autonomic.

When blood pools in the lower body on standing (the central problem in orthostatic intolerance), cardiac output drops. The heart compensates by beating faster, but in impaired cardiovascular reserve, this isn’t always sufficient to maintain adequate cerebral and pulmonary perfusion. The respiratory rate increases not because of hyperventilation in the functional sense, but because the system is genuinely under-perfused.

Additionally, small fibre neuropathy — damage to the fine nerve fibres that regulate peripheral blood vessels and the autonomic nervous system — causes dysfunctional signalling that can manifest as breathlessness and air hunger even at rest, via a different mechanism than either pulmonary disease or classic hyperventilation.

Why it’s commonly confused

Several features make BPD and autonomic breathlessness look superficially similar:

Both present with normal spirometry and often normal chest X-ray
Both are often worse with activity
Both are common in post-viral illness and long COVID
Both can coexist with anxiety (which is itself both a symptom and a trigger)
Both may respond partially to breathing retraining (since reduced sympathetic activation from slower breathing can help both conditions)

The partial response to breathing physiotherapy is perhaps the most misleading feature. Some people with autonomic breathlessness find breathing retraining helpful because it reduces the sympathetic drive and anxiety component — but this doesn’t mean BPD was the underlying cause.

How to distinguish them

Postural pattern

Autonomic breathlessness is typically significantly worse upright and better lying down. BPD can occur in any position but is often worse with anxiety, which doesn’t have the same positional pattern.

Ask yourself: if you lie down for 20–30 minutes, does the breathlessness substantially improve? In orthostatic breathlessness, it often does. In pure BPD, it may not.

Heart rate changes

If your breathlessness is accompanied by a significant heart rate rise on standing (>30 bpm), this points strongly toward an orthostatic/autonomic mechanism. Pure BPD shouldn’t cause orthostatic tachycardia.

The Nijmegen Questionnaire

The Nijmegen questionnaire is a validated 16-item screening tool for breathing pattern disorder. A score above 23 out of 64 is considered positive. It was designed for BPD, not POTS or dysautonomia, and several of its items (breathlessness on exertion, tight chest, fatigue) are non-specific features of both conditions. A high Nijmegen score supports BPD being present or coexisting, but a positive score does not exclude autonomic breathlessness.

Spirometry and gas transfer

Both conditions typically show normal spirometry. However, a reduced DLCO (carbon monoxide transfer factor) on pulmonary function testing suggests pulmonary pathology — ruling this in or out is worth doing.

End-tidal CO2

If available, end-tidal CO2 monitoring can document whether CO2 is actually low during symptoms. Low CO2 supports hyperventilation/BPD. Normal CO2 during symptomatic breathlessness strongly argues against BPD as the primary cause.

CPET

The cardiopulmonary exercise test is the most powerful distinguishing investigation. A CPET can identify the specific pattern of exercise intolerance: whether it’s pulmonary, cardiovascular, or functional. In post-viral autonomic dysfunction, CPET typically shows early anaerobic threshold (switching to anaerobic metabolism at a much lower workload than expected), abnormal heart rate responses, and sometimes chronotropic incompetence. These patterns are not consistent with pure BPD and strongly support an autonomic/cardiovascular mechanism.

BPD on CPET tends to show normal oxygen uptake kinetics and an erratic breathing pattern, without the characteristic cardiovascular abnormalities seen in autonomic dysfunction.

Why the distinction matters for treatment

For breathing pattern disorder: The effective treatment is breathing physiotherapy — retraining breathing rate, pattern, and nose/mouth ratio, addressing the hyperventilation cycle, and managing the anxiety component. Physiotherapy referral is appropriate and often helpful.

For autonomic breathlessness: The effective treatments are orthostatic management (salt, fluid, compression, position) and, in some cases, medications. Breathing physiotherapy may provide some symptomatic relief but doesn’t address the underlying problem. More importantly, physiotherapy aimed at BPD often includes increasing activity and reducing avoidance — this is appropriate for pure BPD but potentially harmful for someone with post-viral autonomic dysfunction and post-exertional malaise.

Getting a POTS or dysautonomia diagnosis and managing the orthostatic component can produce dramatic improvement in breathlessness that no amount of breathing retraining would achieve.

The coexistence problem

Both conditions can coexist, and in long COVID they frequently do. Someone with POTS may also have developed dysfunctional breathing as a secondary response to their symptoms, producing a mixed picture. Treatment in this case should address both components — but it’s important to identify the autonomic contribution so that management isn’t entirely focused on the breathing pattern while missing the primary mechanism.

If you’ve been told it’s BPD but your breathlessness is consistently postural, associated with heart rate rise, and has not responded adequately to breathing retraining over several months, pushing for orthostatic assessment and ideally a CPET is reasonable.

References

Todd S, Shoaib A, McGrogan A, et al. Orthostatic intolerance and breathlessness in long COVID. Eur Respir J. 2022;60(suppl 66):2569.

Kloosterboer SM, Olieslager CS, Ten Doesschate JE, Vermunt M, Scheeren TWL. Respiratory manifestations in patients with postural orthostatic tachycardia syndrome. J Intern Med. 2022;292(5):782–793.

van Dixhoorn J, Duivenvoorden HJ. Efficacy of Nijmegen Questionnaire in recognition of the hyperventilation syndrome. J Psychosom Res. 1985;29(2):199–206.

Heaton RK. Neuropsychological aspects of breathing disorders. Arch Gen Psychiatry. 1981;38(7):815.

Kanjwal K, Karabin B, Kanjwal Y, Grubb BP. Differentiation of convulsive syncope from epilepsy with an implantable loop recorder. Int J Med Sci. 2009;6(6):296–300.