What is the autonomic nervous system, and what is dysautonomia?
What the autonomic nervous system controls, what the term dysautonomia covers, and why it does not refer to a single disease.
- 8 sources
- 3 min read
- Clinical review
- Verified 9 November 2026
Key points
- The autonomic nervous system helps regulate functions that are not under voluntary control, such as blood pressure, heart rate, sweating, digestion, and emptying of the bladder and bowel [1, 2].
- “Dysautonomia” refers to a heterogeneous group of disorders: the problem may be limited to a single autonomic function or involve several systems; causes may be central or peripheral, primary or secondary [3].
- A symptom consistent with autonomic dysfunction does not, on its own, identify a disease: test results are also interpreted in light of the medical history and the clinical examination [2, 4].
- No single test is enough to establish the degree or distribution of autonomic failure [2].
Definition of the autonomic nervous system
What does “dysautonomia” mean?
Which disorders, and which causes?
How is autonomic function assessed?
What the term does not tell you
References and level of evidence
- MedlinePlus (National Library of Medicine); Campellone JV. Autonomic neuropathy. MedlinePlus Medical Encyclopedia (NIH), reviewed October 23, 2024 2024.(expert opinion)Limitations: Consumer health information page from the US National Library of Medicine; not a clinical guideline. Read: full text.Declared conflicts of interest: Not declared (institutional page)
- Cheshire WP et al. Electrodiagnostic assessment of the autonomic nervous system: A consensus statement endorsed by the American Autonomic Society, American Academy of Neurology, and the International Federation of Clinical Neurophysiology. Clinical Neurophysiology, 132(2):666–682 2021. DOI: 10.1016/j.clinph.2020.11.024. PMID: 33419664.(guideline or consensus)Limitations: Practice consensus; indications depend on the clinical context. Population: consensus on autonomic testing. Read: full text.Declared conflicts of interest: No conflicts of interest declared. Corrigendum published (Clin Neurophysiol 2021;132(5):1194) regarding an author's name
- Hovaguimian A. Dysautonomia: Diagnosis and Management. Neurologic Clinics, 41(1):193–213 2023. DOI: 10.1016/j.ncl.2022.08.002. PMID: 36400555.(expert opinion)Limitations: Narrative review; not a formal guideline. Population: general clinical review of dysautonomias. Read: abstract.Declared conflicts of interest: Not reviewed in the part of the source that was read
- Cortez MM, Cook G, Miglis MG, Raj SR, Robbins NM, Singer W, Sletten DM, Stino AM, Vernino S. Utility and best practices for clinical diagnostic testing of the autonomic nervous system: A Consensus Statement Endorsed by the American Autonomic Society and the American Association of Neuromuscular & Electrodiagnostic Medicine. Clinical Autonomic Research 2026. DOI: 10.1007/s10286-026-01238-9. PMID: 42766240.(guideline or consensus)Limitations: Expert consensus; not a comparative trial of all strategies. Population: specialist consensus, autonomic testing. Read: full text (open access, Springer).Declared conflicts of interest: Several authors declare consulting activities or industry funding (including Argenx, CSL Behring, Takeda); others declare none
- Sivakoti K, Cortez MM, Fedorowski A, Fudim M, Lau DH, Novak P, Rowe PC, Schofield JR, Blitshteyn S, International POTS and Dysautonomia Expert Panel. Postural orthostatic tachycardia syndrome (POTS) and dysautonomia: International multidisciplinary expert consensus. American Journal of Medicine 2026. DOI: 10.1016/j.amjmed.2026.08.012. PMID: 42665152.(guideline or consensus)Limitations: Expert consensus; does not replace clinical studies or comparative trials. Population: international Delphi consensus, adults and children, POTS and non-POTS dysautonomia. Read: abstract.Declared conflicts of interest: Not visible in the abstract consulted
- Thijs RD et al. Recommendations for tilt table testing and other provocative cardiovascular autonomic tests in conditions that may cause transient loss of consciousness: Consensus statement of the European Federation of Autonomic Societies (EFAS) endorsed by the American Autonomic Society (AAS) and the European Academy of Neurology (EAN). Clinical Autonomic Research, 31(3):369–384 2021. DOI: 10.1007/s10286-020-00738-6. PMID: 33740206.(guideline or consensus)Limitations: The authors state that this is not a formal evidence-based guideline. Technical recommendations; does not replace the overall clinical assessment. Population: provocative tests for syncope, OH and related presentations. Read: full text (Leiden University repository).Declared conflicts of interest: Several authors declare fees or industry funding outside the submitted work (Medtronic, UCB, Novo Nordisk, Boston Scientific…)
- Raj SR, Fedorowski A, Sheldon RS. Diagnosis and management of postural orthostatic tachycardia syndrome. CMAJ, 194(10):E378–E385 2022. DOI: 10.1503/cmaj.211373. PMID: 35288409.(evidence synthesis)Limitations: Narrative review; recommendations and treatment data limited by the available trials. Population: clinical review of POTS diagnosis and management; criteria and differential diagnosis. Read: full text (cmaj.ca).Declared conflicts of interest: All three authors declare research funding, fees or consulting activities; Raj and Sheldon also declare expert-witness work or patents
- Devigili G et al. Diagnostic criteria for small fibre neuropathy in clinical practice and research. Brain, 142(12):3728–3736 2019. DOI: 10.1093/brain/awz333. PMID: 31665231.(observational study)Limitations: Clinical cohorts; criteria depend on the examination and the methods available. Population: reassessment and validation of diagnostic criteria. Read: full text.Declared conflicts of interest: The authors declare no conflicts of interest; funding: Italian Ministry of Health (Ricerca Corrente)