Dysfunctional breathing: what do we know?
Open accessAbstract
ABSTRACT Dysfunctional breathing (DB) is a respiratory condition characterized by irregular breathing patterns that occur either in the absence of concurrent diseases or secondary to cardiopulmonary diseases. Although the primary symptom is often dyspnea or “air hunger”, DB is also associated with nonrespiratory symptoms such as dizziness and palpitations. DB has been identified across all ages. Its prevalence among adults in primary care in the United Kingdom is approximately 9.5%. In addition, among individuals with asthma, a positive diagnosis of DB is found in a third of women and a fifth of men. Although DB has been investigated for decades, it remains poorly understood because of a paucity of high-quality clinical trials and validated outcome measures specific to this population. Accordingly, DB is often underdiagnosed or misdiagnosed, given the similarity of its associated symptoms (dyspnea, tachycardia, and dizziness) to those of other common cardiopulmonary diseases such as COPD and asthma. The high rates of misdiagnosis of DB suggest that health care professionals do not fully understand this condition and may therefore fail to provide patients with an appropriate treatment. Given the multifarious, psychophysiological nature of DB, a holistic, multidimensional assessment would seem the most appropriate way to enhance understanding and diagnostic accuracy. The present narrative review was developed as a means of summarizing the available evidence about DB, as well as improving understanding of the condition by researchers and practitioners.
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Nonrespiratory symptoms often considered related with DB include palpitations, dizziness, paresthesia and chest tightness.
“Nonrespiratory symptoms often considered to be related with DB include palpitations, dizziness, paresthesia and chest tightness (8,14).”
From How is dysfunctional breathing characterised in the clinical literature? A scoping review (2026) · cites this paper as [8]
The Abstract identifies dizziness and palpitations as nonrespiratory symptoms of dysfunctional breathing, and the Introduction lists paresthesia among its symptoms. The passages do not identify chest tightness as a symptom; the Respiratory muscle function section mentions upper-chest tenderness, which is not the same claim. (LLM, conf=0.87)
Experimental — accuracy not yet measuredThe complex interplay between psychological and physiological symptoms often encountered in other common cardiopulmonary conditions such as asthma and COPD has been suggested to contribute to under recognition of DB and high rates of misdiagnosis.
“This complex interplay between psychological and physiological symptoms often encountered in other common cardiopulmonary conditions such as asthma and COPD has been suggested to contribute to under recognition of DB's and high rates of misdiagnosis (8).”
From How is dysfunctional breathing characterised in the clinical literature? A scoping review (2026) · cites this paper as [8]
Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
Experimental — accuracy not yet measuredFour classification systems for DB have been proposed.
“Four classification systems for DB have been proposed, as referenced in sources (4,7,8,10), with further details provided in Supplementary Materials 2.”
From How is dysfunctional breathing characterised in the clinical literature? A scoping review (2026) · cites this paper as [8]
The ‘Definition and Classification of DB’ section says researchers have proposed alternative classifications, and Table 1 lists classifications by Boulding et al. and Barker and Everard. The available passages do not establish that there are exactly four classification systems. (LLM, conf=0.84)
Experimental — accuracy not yet measuredDue to a lack of a diagnostic criterion, prevalence data for DB could be over or underestimated.
“However, it has been highlighted that due to a lack of a diagnostic criterion, prevalence data for the condition could be over or underestimated (8).”
From How is dysfunctional breathing characterised in the clinical literature? A scoping review (2026) · cites this paper as [8]
There is little consensus in the literature and in clinical practice on how DB is defined, assessed and managed.
“Despite its potentially significant prevalence, there is little consensus in the literature and in clinical practice on how DB is defined, assessed and managed (8,16).”
From How is dysfunctional breathing characterised in the clinical literature? A scoping review (2026) · cites this paper as [8]
The prevalence of misdiagnosis in cases of DB indicates a limited understanding of the condition among healthcare professionals, which may hinder the delivery of appropriate treatment to affected patients.
“The prevalence of misdiagnosis in cases of DB indicates a limited understanding of the condition among healthcare professionals, which may hinder the delivery of appropriate treatment to affected patients (8).”
From How is dysfunctional breathing characterised in the clinical literature? A scoping review (2026) · cites this paper as [8]
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Cites
Miller, M. R., Hankinson, J., Brusasco, V., Burgos, F., Casaburi, R., Coates, A., Crapo, R., Enright, P., van der Grinten, C. P. M., Gustafsson, P., et al. (2005) · European Respiratory Journal · doi:10.1183/09031936.05.00034805 · Cited by 15,627 · see citing works
Efficacy of Nijmegen questionnaire in recognition of the hyperventilation syndrome
van Dixhoorn, J., & Duivenvoorden, H. J. (1985) · Journal of Psychosomatic Research · doi:10.1016/0022-3999(85)90042-x · Cited by 445 · see citing works
Dysfunctional breathing: a review of the literature and proposal for classification
Boulding, R., Stacey, R., Niven, R., & Fowler, S. J. (2016) · European Respiratory Review · doi:10.1183/16000617.0088-2015 · Cited by 372 · cited 2× · see citing works
“, the “fi ght-or-fl ight response” occurs) in all individuals, patients with DB commonly experience abnormal psychophysiological responses when facing similar scenarios.(9) DB induces signifi cant changes in the respiratory rate, breath-holding time, and depth of breathing that are primarily mediated by current or pre…”
BackgroundThomas, M., McKinley, R. K., Freeman, E., & Foy, C. (2001) · BMJ · doi:10.1136/bmj.322.7294.1098 · Cited by 294 · see citing works
Hornsveld, H., Garssen, B., Dop, M. F., van Spiegel, P., & de Haes, J. (1996) · The Lancet · doi:10.1016/s0140-6736(96)02024-7 · Cited by 168 · see citing works
The Nijmegen Questionnaire and dysfunctional breathing
van Dixhoorn, J., & Folgering, H. (2015) · ERJ Open Research · doi:10.1183/23120541.00001-2015 · Cited by 161 · see citing works
Diagnostic tests of hyperventilation syndrome
Vansteenkiste, J., Rochette, F., & Demedts, M. (1991) · European Respiratory Journal · doi:10.1183/09031936.93.04040393 · Cited by 103 · see citing works
Courtney, R., Greenwood, K. M., & Cohen, M. (2011) · Journal of Bodywork and Movement Therapies · doi:10.1016/j.jbmt.2010.06.004 · Cited by 96 · see citing works
A comparison between patients with dysfunctional breathing and patients with asthma
Hagman, C., Janson, C., & Emtner, M. (2008) · The Clinical Respiratory Journal · doi:10.1111/j.1752-699x.2007.00036.x · Cited by 67 · see citing works
Breathing retraining - A five-year follow-up of patients with dysfunctional breathing
Hagman, C., Janson, C., & Emtner, M. (2011) · Respiratory Medicine · doi:10.1016/j.rmed.2011.03.006 · Cited by 66 · see citing works
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Research works printed but not linked: 56
- [3]Barker NJ Jones M O'Connell NE Everard ML Breathing exercises for dysfunctional breathing/hyperventilation syndrome in children Cochrane Database Syst Rev 2013 12 12 CD010376 CD010376 10.1002/14651858.CD010376 PMC11366082 24347088 · DOI
- [4]Barker N Everard ML Getting to grips with "dysfunctional breathing " Paediatr Respir Rev 2015 16 1 53 61 10.1016/j.prrv.2014.10.001 25499573 · DOI · Paper page
- [5]Thomas M McKinley RK Freeman E Foy C Price D The prevalence of dysfunctional breathing in adults in the community with and without asthma Prim Care Respir J 2005 14 2 78 82 10.1016/j.pcrj.2004.10.007 16701702 PMC6743552 · DOI · Paper page
- [6]Jones M Troup F Nugus J Roughton M Hodson M Rayner C Does manual therapy provide additional benefit to breathing retraining in the management of dysfunctional breathing A randomised controlled trial Disabil Rehabil 2015 37 9 763 770 10.3109/09638288.2014.941020 25026508 · DOI
- [7]De Groot EP Duiverman EJ Brand PL Dysfunctional breathing in children with asthma a rare but relevant comorbidity Eur Respir J 2013 41 5 1068 1073 10.1183/09031936.00130212 23018913 · DOI · Paper page
- [10]Han JN Stegen K De Valck C Clément J Van de Woestijne KP Influence of breathing therapy of complaints, anxiety, and breathing pattern with hyperventilation syndrome and anxiety disorders J Psychosom Res 1996 41 5 481 493 10.1016/S0022-3999(96)00220-6 9032712 · DOI · Paper page
- [11]Gilbert C Emotional sources of dysfunctional breathing J Bodyw Mov Ther 1998 2 4 224 230 10.1016/S1360-8592(98)80019-3 · DOI · Paper page
- [12]DeGuire S Gevirtz R Hawkinson D Dixon K Breathing retraining a three-year follow-up study of treatment for hyperventilation syndrome and associated functional cardiac symptoms Biofeedback Self Regul 1996 21 2 191 198 10.1007/BF02284695 8805966 · DOI
- [13]Howell JB The hyperventilation syndrome a syndrome under threat? Thorax 1997 52 3 S30 S34 10.1136/thx.52.2008.S30 9381424 PMC1765877 · DOI · Paper page
- [14]Bott J Blumenthal S Buxton M Ellum S Falconer C Garrod R Guidelines for the physiotherapy management of the adult, medical, spontaneously breathing patient Thorax 2009 64 1 i1 51 10.1136/thx.2008.110726 19406863 · DOI · Paper page
- [15]Jones M Harvey A Marston L O'Connell NE Breathing exercises for dysfunctional breathing/hyperventilation syndrome in adults Cochrane Database Syst Rev 2013 5 CD009041 CD009041 10.1002/14651858.CD009041.pub2 23728685 PMC11379427 · DOI · Paper page
- [16]Gardner WN The pathophysiology of hyperventilation disorders Chest 1996 109 2 516 534 10.1378/chest.109.2.516 8620731 · DOI · Paper page
- [18]Jack S Rossiter HB Pearson MG Ward SA Warburton CJ Whipp BJ Ventilatory responses to inhaled carbon dioxide, hypoxia, and exercise in idiopathic hyperventilation Am J Respir Crit Care Med 2004 170 2 118 125 10.1164/rccm.200207-720OC 15059786 · DOI
- [19]Kerr WJ Gliebe PA Dalton JW Physical Phenomena Associated with Anxiety States The Hyperventilation Syndrome Cal West Med 1938 48 1 12 16 18744341 PMC1705784
- [20]Warburton CJ Jack S Can you diagnose hyperventilation Chron Respir Dis 2006 3 3 113 115 10.1191/1479972306cd116ed 16916004 · DOI · Paper page
- [21]Jack S Rossiter HB Warburton CJ Whipp BJ Behavioral influences and physiological indices of ventilatory control in subjects with idiopathic hyperventilation Behav Modif 2003 27 5 637 652 10.1177/0145445503256318 14531159 · DOI
- [24]Grammatopoulou EP Skordilis EK Georgoudis G Haniotou A Evangelodimou A Fildissis G Hyperventilation in asthma a validation study of the Nijmegen Questionnaire--NQ J Asthma 2014 51 8 839 846 10.3109/02770903.2014.922190 24823322 · DOI · Paper page
- [26]Hegel MT Abel GG Etscheidt M Cohen-Cole S Wilmer CI Behavioral treatment of angina-like chest pain in patients with hyperventilation syndrome J Behav Ther Exp Psychiatry 1989 20 1 31 39 10.1016/0005-7916(89)90005-0 2671050 · DOI
- [27]Grossman P de Swart JC Diagnosis of hyperventilation syndrome on the basis of reported complaints J Psychosom Res 1984 28 2 97 104 10.1016/0022-3999(84)90001-1 6429325 · DOI
- [29]American Thoracic SocietyAmerican College of Chest Physicians ATS/ACCP Statement on cardiopulmonary exercise testing Am J Respir Crit Care Med 2003 167 2 211 277 10.1164/rccm.167.2.211 12524257 · DOI · Paper page
- [30]Courtney R Cohen M Investigating the claims of Konstantin Buteyko, M D., Ph.D.: The relationship of breath holding time to end tidal CO2 and other proposed measures of dysfunctional breathing J Altern Complement Med 2008 14 2 115 123 10.1089/acm.2007.7204 18315509 · DOI · Paper page
- [31]Courtney R Greenwood KM Preliminary investigation of a measure of dysfunctional breathing symptoms The Self Evaluation of Breathing Questionnaire (SEBQ) Int J Osteopath Med 2009 12 4 121 127 10.1016/j.ijosm.2009.02.001 · DOI · Paper page
- [32]Agache I Ciobanu C Paul G Rogozea L Dysfunctional breathing phenotype in adults with asthma - incidence and risk factors Clin Transl Allergy 2012 2 1 18 18 10.1186/2045-7022-2-18 22992302 PMC3502326 · DOI · Paper page
- [33]Combes P Fauvage B Combined effects of hypocapnia and nicardipine on airway resistance a pilot study Eur J Clin Pharmacol 1997 51 5 385 388 10.1007/s002280050218 9049579 · DOI
- [34]Brijker F van den Elshout FJ Heijdra YF Bosch FH Folgering HT Effect of acute metabolic acid/base shifts on the human airway calibre Respir Physiol 2001 124 2 151 158 10.1016/S0034-5687(00)00196-1 11164206 · DOI
- [36]Courtney R van Dixhoorn J Greenwood KM Anthonissen EL Medically unexplained dyspnea partly moderated by dysfunctional (thoracic dominant) breathing pattern J Asthma 2011 48 3 259 265 10.3109/02770903.2011.554942 21341969 · DOI · Paper page
- [37]Courtney R Cohen M Reece J Comparison of the Manual Assessment of Respiratory Motion (MARM) and the Hi Lo Breathing Assessment in determining a simulated breathing pattern Int J Osteopath Med 2009 12 3 86 91 10.1016/j.ijosm.2008.10.002 · DOI · Paper page
- [38]De Troyer A Estenne M Functional anatomy of the respiratory muscles Clin Chest Med 1988 9 2 175 193 3292122
- [39]Janssens L Pijnenburg M Claeys K McConnell AK Troosters T Brumagne S Postural strategy and back muscle oxygenation during inspiratory muscle loading Med Sci Sports Exerc 2013 45 7 1355 1362 10.1249/MSS.0b013e3182853d27 23470314 · DOI
- [40]Sieck GC Ferreira LF Reid MB Mantilla CB Mechanical properties of respiratory muscles Compr Physiol 2013 3 4 1533 1567 10.1002/cphy.c130003 PMC3977503 24265238 · DOI
- [41]Hruska R Jr Influences of dysfunctional respiratory mechanics on orofacial pain Dent Clin North Am 1997 41 2 211 227 9142480
- [42]Wolf SG Diaphragmatic spasm: a neglected cause of dyspnoea and chest pain Integr Physiol Behav Sci 1994 29 1 74 76 10.1007/BF02691282 8018554 · DOI
- [43]O'Donnell DE Hyperinflation, dyspnea, and exercise intolerance in chronic obstructive pulmonary disease Proc Am Thorac Soc 2006 3 2 180 184 10.1513/pats.200508-093DO 16565429 · DOI · Paper page
- [44]Lewit K Manipulative therapy in rehabilitation of the locomotor system 1999 3 Oxford Butterworth Heinemann
- [45]Siafakas NM Vermeire P Pride NB Paoletti P Gibson J Howard P Optimal assessment and management of chronic obstructive pulmonary disease (COPD) The European Respiratory Society Task Force Eur Respir J 1995 8 8 1398 1420 10.1183/09031936.95.08081398 7489808 · DOI
- [47]Cluff RA Chronic hyperventilation and its treatment by physiotherapy discussion paper J R Soc Med 1984 77 10 855 862 10.1177/014107688407701011 6387113 PMC1440257 · DOI
- [48]Law N Ruane LE Low K Hamza K Bardin PG Dysfunctional breathing is more frequent in chronic obstructive pulmonary disease than in asthma and in health Respir Physiol Neurobiol 2018 247 20 23 10.1016/j.resp.2017.08.011 28870869 · DOI
- [49]Courtney R van Dixhoorn J Cohen M Evaluation of breathing pattern comparison of a Manual Assessment of Respiratory Motion (MARM) and respiratory induction plethysmography Appl Psychophysiol Biofeedback 2008 33 2 91 100 10.1007/s10484-008-9052-3 18320303 · DOI · Paper page
- [50]American Thoracic Society/European Respiratory Society ATS/ERS Statement on respiratory muscle testing Am J Respir Crit Care Med 2002 166 4 518 624 10.1164/rccm.166.4.518 12186831 · DOI
- [51]Yasuma F Hayano J Respiratory sinus arrhythmia why does heartbeat synchronize with respiratory rhythm? Chest 2004 125 2 683 690 10.1378/chest.125.2.683 14769752 · DOI · Paper page
- [52]Joseph CN Porta C Casucci G Casiraghi N Maffeis M Rossi M Slow breathing improves arterial baroreflex sensitivity and decreases blood pressure in essential hypertension Hypertension 2005 46 4 714 718 10.1161/01.HYP.0000179581.68566.7d 16129818 · DOI · Paper page
- [53]Volterrani M Scalvini S Mazzuero G Lanfranchi P Colombo R Clark AL Decreased heart rate variability in patients with chronic obstructive pulmonary disease Chest 1994 106 5 1432 1437 10.1378/chest.106.5.1432 7956396 · DOI
- [54]Suzuki M Hiroshi T Aoyama T Tanaka M Ishii H Kisohara M Nonlinear measures of heart rate variability and mortality risk in hemodialysis patients Clin J Am Soc Nephrol 2012 7 9 1454 1460 10.2215/CJN.09430911 22723446 PMC3430947 · DOI
- [55]Stein PK Nelson P Rottman JN Howard D Ward SM Kleiger RE Heart rate variability reflects severity of COPD in PiZ alpha1-antitrypsin deficiency Chest 1998 113 2 327 333 10.1378/chest.113.2.327 9498947 · DOI
- [56]Courtney R Cohen M van Dixhoorn J Relationship between dysfunctional breathing patterns and ability to achieve target heart rate variability with features of "coherence" during biofeedback Altern Ther Health Med 2011 17 3 38 44 22164811
- [58]Malmberg LP Tamminen K Sovijärvi AR Orthostatic increase of respiratory gas exchange in hyperventilation syndrome Thorax 2000 55 4 295 301 10.1136/thorax.55.4.295 10722769 PMC1745734 · DOI · Paper page
- [59]Chenivesse C Similowski T Bautin N Fournier C Robin S Wallaert B Severely impaired health-related quality of life in chronic hyperventilation patients exploratory data Respir Med 2014 108 3 517 523 10.1016/j.rmed.2013.10.024 24269004 · DOI
- [60]Gosselink R De Vos J van den Heuvel SP Segers J Decramer M Kwakkel G Impact of inspiratory muscle training in patients with COPD what is the evidence? Eur Respir J 2011 37 2 416 425 10.1183/09031936.00031810 21282809 · DOI · Paper page
- [61]van de Weert-van Leeuwen PB Slieker MG Hulzebos HJ Kruitwagen CL van der Ent CK Arets HG Chronic infection and inflammation affect exercise capacity in cystic fibrosis Eur Respir J 2012 39 4 893 898 10.1183/09031936.00086211 21885387 · DOI
- [62]Tobin MJ Perez W Guenther SM D'Alonzo G Dantzker DR Breathing pattern and metabolic behavior during anticipation of exercise J Appl Physiol (1985) 1986 60 4 1306 1312 10.1152/jappl.1986.60.4.1306 3700308 · DOI
- [63]Conway AV Timmons B Ley R Behavioral and psychological approaches to breathing disorders Breathing and feeling 1994 London Springer 243 251 10.1007/978-1-4757-9383-3_18 · DOI
- [64]Studer R Danuser B Hildebrandt H Arial M Gomez P Hyperventilation complaints in music performance anxiety among classical music students J Psychosom Res 2011 70 6 557 564 10.1016/j.jpsychores.2010.11.004 21624579 · DOI
- [65]Han JN Stegen K Simkens K Cauberghs M Schepers R Van den Bergh O Unsteadiness of breathing in patients with hyperventilation syndrome and anxiety disorders Eur Respir J 1997 10 1 167 176 10.1183/09031936.97.10010167 9032511 · DOI · Paper page
- [66]Thomas M McKinley RK Freeman E Foy C Prodger P Price D Breathing retraining for dysfunctional breathing in asthma a randomised controlled trial Thorax 2003 58 2 110 115 10.1136/thorax.58.2.110 12554890 PMC1746567 · DOI · Paper page
- [67]Ritz T Rosenfield D Meuret AE Bobb C Steptoe A Hyperventilation symptoms are linked to a lower perceived health in asthma patients Ann Behav Med 2008 35 1 97 104 10.1007/s12160-007-9014-7 18347909 · DOI
- [69]Jacobson E Progressive relaxation 1938 2 Oxford Univ Chicago Press
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Reilly, C. C., Floyd, S. V., Lee, K., Warwick, G., James, S., Gall, N., & Rafferty, G. F. (2020) · Autonomic Neuroscience · doi:10.1016/j.autneu.2019.102601 · Cited by 48 · see citing works
Physiotherapy assessment of breathing pattern disorder: a qualitative evaluation
Grillo, L., Russell, A.-M., Shannon, H., & Lewis, A. (2023) · BMJ Open Respiratory Research · doi:10.1136/bmjresp-2022-001395 · Cited by 27 · see citing works
How is dysfunctional breathing characterised in the clinical literature? A scoping review
Sanchez-Bracero, D., Baker, K., Archer, T., Shaw, T., & Palmer, J. (2026) · Respiratory Medicine · doi:10.1016/j.rmed.2025.108546 · Cited by 1 · see citing works
- Authors
- Vidotto, L. S., Carvalho, C. R. F. D., Harvey, A., & Jones, M.
- Affiliations
- Brunel University of London (GB)
- Universidade de São Paulo (BR)
- Venue
- Jornal Brasileiro de Pneumologia
- Publisher
- FapUNIFESP (SciELO)
- Published
- 2019
- Volume
- 45
- Issue
- 1
- Pages
- e20170347-e20170347
- ISSN
- 1806-3713 (ISSN-L)
- 1806-3756
- PMC
- PMC6534396
- OpenAlex
- W2913295725
- Cited by
- 116
- References
- 10
- Citations by year
- 2026: 16 · 2025: 31 · 2024: 16 · 2023: 13 · 2022: 14 · 2021: 14 · 2020: 10 · 2019: 2
- FWCI
- 1.68
- Type
- journal article
- Language
- en
- Open access
- diamond
- doi.org
- Licence
- Locations
- Jornal Brasileiro de Pneumologia (publishedVersion, cc-by-nc)
- PubMed Central (publishedVersion, cc-by-nc)
- PubMed (publishedVersion)
- LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) (publishedVersion, other-oa)
- LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas) (submittedVersion, other-oa)
- Americanae (AECID Library) (submittedVersion, cc-by-nc)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- Brunel University Research Archive (BURA) (Brunel University London) (submittedVersion)
- Funders
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior ((Code 001))
- Topics
- Health Sciences › Medicine › Pulmonary and Respiratory Medicine › Respiratory and Cough-Related Research
- Health Sciences › Medicine › Psychiatry and Mental health › Psychosomatic Disorders and Their Treatments
- Health Sciences › Medicine › Physiology › Asthma and respiratory diseases
- Keywords
- dysfunctional breathing, dyspnea, air hunger, dizziness, palpitations, asthma, chronic obstructive pulmonary disease, misdiagnosis, prevalence, psychophysiological assessment, multidimensional assessment, outcome measures
- MeSH terms
- Heart, Humans, Hyperventilation, Lung, Respiration Disorders, Respiratory Muscles, Exercise Tolerance
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