top of page
Search

Autonomic Dysfunction and the Ehlers-Danlos Syndromes

Ehlers-Danlos Syndromes, Autonomic Dysfunction, and the Link Between Them


The Ehlers-Danlos Syndromes (EDS) are a group of heritable connective tissue disorders, characterised by joint hypermobility (abnormally large range of joint motion), skin hyperextensibility (abnormally stretchy skin), and tissue fragility. There are 13 types of EDS, ranging from rare to ultra-rare, each with their own unique features. While the incidence of other types of EDS is similar in men and women, the hypermobile type (hEDS) is more commonly diagnosed in women than men. The cause of this discrepancy is unknown, but it has been suggested that it may be due to women presenting with more severe manifestations, which may be easier to diagnose. Hypermobility (in the absence of connective tissue disorder) is also more common in women, as well as children and people of Afro-Caribbean or Asian descent. However, current understanding is that EDS has no predisposition to certain ethnicities. 


Autonomic dysfunction, or dysautonomia, is an umbrella term for a group of disorders which cause aspects of the autonomic nervous system (ANS) to work ineffectively. Conditions under this umbrella affect a huge variety of body systems due to the widespread innervation of the ANS. Unlike EDS, autonomic dysfunction is not considered rare, with an estimated 70 million people across the globe are living with some type of dysautonomia. This is compared to an estimate of less than 0.1% of the world population living with any type of EDS.


There is a higher prevalence of many types of autonomic dysfunction in people with EDS than the general population, but understanding this relationship requires more research. Current causal suggestions range from autoimmunity and high levels of histamine to low circulating blood volume and problems with the spinal cord. 


EDS and Orthostatic Intolerance


The type of dysautonomia most commonly affecting people with EDS is orthostatic intolerance. Orthostatic intolerance is an umbrella term for conditions in which symptoms are experienced upon standing up. The most common types of orthostatic intolerance are orthostatic hypotension and Postural Orthostatic Tachycardia Syndrome.


Orthostatic hypotension (OH), also referred to as postural hypotension, is diagnosed when a fall in systolic blood pressure of 20mmHg or greater and/or a fall in diastolic blood pressure of 10mmHg or greater is observed within three minutes of standing. In patients with hypertension, a fall in systolic blood pressure must be at least 30mmHg for OH to be diagnosed. OH is more common in certain groups, such as in the elderly population, where changes in the ANS through ageing and drug interactions/side effects are just some relevant factors. Symptoms may be more frequent in women, who typically have more active parasympathetic nervous systems, higher oestrogen levels, and lower centres of gravity, all of which can impact the body’s ability to compensate for the drop in blood pressure when standing. Some differences in orthostatic tolerance between ethnic groups have also been documented, but significant findings are inconsistent.


Postural Orthostatic Tachycardia Syndrome (PoTS), also known as postural tachycardia syndrome, is diagnosed when the following criteria are met:

- Recurring symptoms of orthostatic intolerance, persisting for at least three months, interfering with daily living activities and improving quickly after lying down.

- A sustained increase in heart rate of at least 30 bpm in adults (aged 20 or over) or 40 bpm in adolescents (aged 12 to 19) within 10 minutes of standing in the absence of orthostatic hypotension.


"Symptoms may be more frequent in women, who typically have more active parasympathetic nervous systems, higher oestrogen levels, and lower centres of gravity"

PoTS is particularly prevalent in women, with its average onset occurring during adolescence. Further research examining a more diverse range of participants is needed to determine if ethnicity is a potential risk factor. Importantly, the diagnosis of both conditions requires ruling out other issues  which could be causing the symptoms.


Treatments for OH and PoTS are very similar. Both focus on employing non-pharmacological interventions before exploring drug options, including increasing salt and fluid intake and using compression garments (e.g. stockings or abdominal binders). Particular ‘counter moves’ such as clenching buttocks and core muscles, or rocking up and down on tiptoes can reduce symptoms while standing. If non-pharmacological interventions are proving insufficient, short-acting vasopressors such as midodrine may be prescribed, which can help to reduce symptoms by constricting blood vessels.


It is suggested that orthostatic intolerance may be more common in people with EDS because the walls of blood vessels are more able to stretch than the blood vessels of people with normal connective tissue; however, more targeted research needs to be done to fully understand the connection.


EDS and Gastrointestinal Dysmotility


Gastrointestinal (GI) dysmotility refers to conditions in which food passes through the digestive system abnormally slowly. This can be caused by dysfunction of the muscles - or the nerves that innervate them - in any area of the GI tract. Gastroparesis is one type of GI dysmotility which may have a higher prevalence in a particular subset of EDS patients. 


Gastroparesis, or dysmotility of the stomach, is characterised by the delayed emptying of solids from the stomach in the absence of a mechanical blockage. This can be assessed using gastric emptying scintigraphy, and confirmed by a CT or MRI scan. Gastroparesis can cause nausea and vomiting, which can lead to reduced food and fluid intake. If this is not managed correctly, it can lead to malnutrition. Blood tests can be used to gauge the severity of malnutrition, if present.


"There is a higher prevalence of many types of autonomic dysfunction in people with EDS than the general population"

Dietary changes are typically one of the first treatments recommended; particularly, reducing fat and fibre intake, as these specific food groups can delay gastric emptying. Reducing portion sizes and increasing frequency of meals (eating ‘little and often’) may also improve nutrition. Antiemetics may be prescribed to reduce nausea and vomiting; however, there is limited evidence from trials to support their use. If conventional interventions are insufficient, enteral feeding may be used to help individuals with gastroparesis maintain a healthy weight. For example, a nasojejunal tube (more commonly known as an NJ tube) may be used to bypass the stomach and deposit nutrition directly in the small bowel for absorption.


The link between EDS and GI dysmotility is not fully understood. Due to the higher prevalence of both PoTS and gastroparesis in individuals with EDS, autonomic dysfunction is speculated to be the primary cause. More research, however, needs to be done to better investigate the link between EDS and general autonomic dysfunction. Further research is also required to better understand if sex, age or ethnicity influences incidence.


Conclusion


Overall, this article only looks into a few key examples from two broad areas of autonomic dysfunction, but it has also been linked to other areas, including temperature dysregulation, disturbed bladder function, and sleep problems. Evidence of a causal link between EDS and autonomic dysfunction is far from robust; however, their correlation demonstrated by the high prevalence of a variety of types of dysautonomia should be sufficient to prove that this link must be further investigated.


Resources and Support


Need support with any of the topics discussed in this article? Visit the links below.


Support | The Ehlers-Danlos Society: https://www.ehlers-danlos.com/support/

Ehlers-Danlos Support UK: https://www.ehlers-danlos.org/

Find Support | Dysautonomia Support Network: https://www.dysautonomiasupport.org/find-support/

Find a Support Group | Dysautonomia International: http://www.dysautonomiainternational.org/page.php?ID=24 

Managing PoTS | PoTS UK: https://www.potsuk.org/managingpots/



References


PoTS UK (n.d.). PoTS - Postural Tachycardia Syndrome. [online] PoTS UK. Available at: https://www.potsuk.org/ [Accessed 23 May 2025].

Pyeritz, R.E. (2000). Ehlers–Danlos Syndrome. New England Journal of Medicine, [online] 342(10), pp.730–732. doi:https://doi.org/10.1056/nejm200003093421009.

Siddiqi, S. (2018). Dysmotility: symptoms, causes and treatment | Top Doctors. [online] Top Doctors UK. Available at: https://www.topdoctors.co.uk/medical-dictionary/dysmotility/ [Accessed 6 May 2025].

The Dysautonomia Project (2023). The Dysautonomia Project - An Educational Resource For Autonomic Disorder. [online] The Dysautonomia Project. Available at: https://thedysautonomiaproject.org/ [Accessed 6 May 2025].

The Ehlers-Danlos Society (2016). The Ehlers-Danlos Society. [online] The Ehlers-Danlos Society. Available at: https://www.ehlers-danlos.com/ [Accessed 6 May 2025].

Wu, W. and Ho, V. (2024). An overview of Ehlers Danlos syndrome and the link between postural orthostatic tachycardia syndrome and gastrointestinal symptoms with a focus on gastroparesis. Frontiers in Neurology, [online] 15. doi:https://doi.org/10.3389/fneur.2024.1379646.


This article was written by Ciara Lee and edited by Julia Dabrowska, with graphics produced by Suzana Sultan. If you enjoyed this article, be the first to be notified about new posts by signing up to become a WiNUK member (top right of this page)! Interested in writing for WiNUK yourself? Contact us through the blog page and the editors will be in touch.

Comments

bottom of page