Autonomic Dysfunction (including Orthostatic Hypotension, Postural Tachycardia syndrome and Vasovagal Syncope)

Autonomic dysfunction (sometimes also referred to as dysautonomia) is an umbrella term used to describe any malfunction of the autonomic nervous system, and can occur in many different medical conditions.

Autonomic dysfunction is commonly associated with EDS, especially the hypermobile type. Patients experience a symptom called orthostatic intolerance - the development of symptoms in the upright position that are usually relieved by lying down. The commonest syndromes of orthostatic intolerance found in hEDS/HSD are orthostatic hypotension, postural tachycardia syndrome (PoTS) and recurrent vasovagal syncope. There is much crossover in the symptoms of these three syndromes, which include presyncope/syncope, palpitations, fatigue, sweating, headache, exercise intolerance, blurring of vision and nausea. Symptoms of all three syndromes are known to be highly debilitating.

Orthostatic hypotension is defined a drop in blood pressure of over 20/10 mmHg when moving from a recumbent to an upright position.

PoTS is defined as

a sustained increase in heart rate of 30 beats per minute or more (in the absence of orthostatic hypotension) when moving from recumbent to standing position

heart rate increase should be over 40 bpm in those aged 12-19 years

heart rate increase must be associated with frequent symptoms of PoTS

The diagnoses of POTS, OH and vasovagal syncope are not mutually exclusive in a patient. Physiological treatments for all three conditions are broadly similar and include increased fluids, salt, dietary adjustments, postural manoeuvres to prevent fainting and graduated exercise regimens. Medication can also be of benefit.

Further information

Mast Cell Activation Syndrome (MCAS)

Mast cell activation syndrome (MCAS) is an immunological condition in which mast cells inappropriately and excessively release chemical mediators, resulting in a wide range of chronic inflammatory and immune symptoms, sometimes including anaphylaxis or near-anaphylaxis attacks. Mast cells form a part of our innate immunity and are to be found in every part of the body.

MCAS and its relationship to hEDS is a new but frequent topic of discussion amongst patients and clinicians alike. Many patients, particularly in the USA, are being diagnosed with both conditions and there are several observational studies suggesting an overlap. However, the evidence of a definitive link, and research into what that link might be is at a very early stage. Treatment of MCAS is covered in the later section.

Simple introductory explanation of MCAS

Review article published by the International Consortium in 2017 on MCAS in EDS

The first significant cohort study of patients with MCAS describes in detail the symptoms and co-existent conditions and should help us to recognise MCAS