Dysautonomia: Symptoms, Types, Causes and Treatment

Dysautonomia refers to a group of medical conditions caused by malfunction of the autonomic nervous system (ANS). The ANS is responsible for many involuntary bodily functions, including heart rate, blood pressure, digestion, temperature regulation, and more. When the ANS is disrupted, a wide range of symptoms and disorders can occur, sometimes severely impacting quality of life. As research advances, our understanding of dysautonomia continues to grow, uncovering its many forms, causes, and potential treatments.

Symptoms of Dysautonomia

Dysautonomia manifests in a variety of ways, often presenting with symptoms that can be confusing or mistaken for other conditions. Recognizing these symptoms is crucial for timely diagnosis and management.

Symptom	Description	Common Disorders	Source(s)
Orthostatic Intolerance	Dizziness, lightheadedness, or fainting when standing	POTS, EDS, Long-COVID	1 4 5 9 12
Palpitations	Sensation of rapid or irregular heartbeat	POTS, EDS, PD	1 2 9 12
Blood Pressure Fluctuations	Sudden drops or spikes, especially on standing	PD, FD, TBI, POTS	2 6 7 13
Fatigue	Persistent tiredness, activity intolerance	Long-COVID, EDS, POTS	4 5 9 12
Sweating Abnormalities	Profuse sweating or lack thereof	TBI, FD, PD	3 7 13
GI Symptoms	Nausea, vomiting, constipation, dysmotility	FD, PD, EDS	6 7 8 9 18

Table 1: Key Symptoms

Understanding the Symptoms

The symptoms of dysautonomia reflect the wide-ranging functions governed by the ANS. They can be subtle or dramatic, intermittent or constant, and differ depending on the underlying type and cause.

Orthostatic Intolerance and Cardiovascular Symptoms

A hallmark of many dysautonomia cases is orthostatic intolerance—difficulty maintaining blood pressure and heart rate when upright. People may feel dizzy, lightheaded, or faint upon standing. In conditions like Postural Orthostatic Tachycardia Syndrome (POTS), heart rate increases by more than 30 beats per minute upon standing, often without a significant drop in blood pressure. In some cases, orthostatic hypotension (a significant drop in blood pressure upon standing) is observed, especially in Parkinson's disease and familial dysautonomia 1 2 4 9 12.

Palpitations and Heart Rate Variability

Palpitations are common, particularly in POTS and related disorders. Research shows that patients with Ehlers-Danlos syndrome (EDS) and hypermobility spectrum disorders often report palpitations, chest discomfort, and other cardiac symptoms, especially when upright 1 9 12.

Fatigue and Activity Intolerance

Persistent fatigue is a frequent and debilitating symptom in dysautonomia. In long-COVID syndrome, fatigue and exercise intolerance are prominent and often overlap with orthostatic symptoms 4 5.

Excessive or Absent Sweating

Dysautonomia can disrupt normal sweating, leading to episodes of excessive sweating (as seen in autonomic storms after traumatic brain injury) or a lack of sweating, which impairs temperature regulation (notably in familial dysautonomia) 3 6 7 13.

Gastrointestinal and Other Symptoms

The ANS also controls digestion and urination. GI symptoms—such as nausea, vomiting, constipation, and dysmotility—are particularly common in familial dysautonomia, Parkinson’s disease, and EDS. Some individuals may also have urinary symptoms or problems with tear production and temperature regulation 6 7 8 18.

Types of Dysautonomia

Dysautonomia is not a single disease, but rather a group of disorders with different underlying mechanisms and clinical presentations.

Type	Defining Features	Typical Onset	Source(s)
Familial Dysautonomia (FD)	Genetic, sensory/autonomic loss, Ashkenazi Jewish ancestry	Birth/infancy	6 7 8 10 11
Postural Orthostatic Tachycardia Syndrome (POTS)	Orthostatic tachycardia, often in young adults	Adolescence/young adult	1 4 9 12
Neurogenic Orthostatic Hypotension	Drop in BP on standing, often with neurodegenerative disease	Older adults	2 18
Dysautonomia in EDS/HSD	Orthostatic symptoms, palpitations, GI issues	Any age (often young women)	1 9 12
Dysautonomia after TBI	Paroxysmal autonomic storms, HR/BP changes	Post-injury	3 13 14 15
Long-COVID Dysautonomia	Orthostatic intolerance, fatigue	Post-viral	4 5
Autoimmune Dysautonomia	Dysautonomia with evidence of autoimmunity	Any age	17

Table 2: Major Types of Dysautonomia

Exploring the Types

The spectrum of dysautonomia includes both inherited and acquired forms.

Familial Dysautonomia (FD)

FD, also called Riley-Day syndrome or hereditary sensory and autonomic neuropathy type III, is a rare genetic disorder almost exclusively affecting individuals of Ashkenazi Jewish ancestry. It is present from birth, with profound sensory and autonomic dysfunction, including blood pressure instability, absence of tears, and frequent vomiting crises. FD is caused by mutations in the ELP1 (IKBKAP) gene, affecting the development and survival of autonomic and sensory neurons 6 7 8 10 11.

Postural Orthostatic Tachycardia Syndrome (POTS)

POTS is a common acquired dysautonomia, especially in adolescents and young adults. It is characterized by excessive heart rate increase upon standing, without a significant drop in blood pressure. Symptoms include palpitations, dizziness, and often fatigue. POTS can be triggered by infections, trauma, or even stress, and is frequently seen in people with joint hypermobility or after viral illnesses such as COVID-19 1 4 9 12.

Neurogenic Orthostatic Hypotension

This type is most often associated with neurodegenerative diseases, such as Parkinson's disease. Here, degeneration of autonomic nerves leads to an inability to maintain blood pressure upon standing, resulting in dizziness or fainting 2 18.

Dysautonomia in EDS/Hypermobility Spectrum Disorders

Patients with Ehlers-Danlos syndrome (EDS) or hypermobility spectrum disorders (HSD) frequently display dysautonomia, notably orthostatic intolerance and POTS. Symptoms may also include GI dysfunction, bladder issues, and temperature regulation problems 1 9 12.

Dysautonomia after Traumatic Brain Injury (TBI)

Following severe TBI, patients may experience “autonomic storms” with unpredictable fluctuations in heart rate, blood pressure, sweating, and temperature. These episodes can be prolonged and challenging to manage 3 13 14 15.

Long-COVID Dysautonomia

COVID-19 infection can trigger new-onset dysautonomia, with symptoms similar to POTS and chronic fatigue, often persisting for months after the initial illness 4 5.

Autoimmune Dysautonomia

In some patients, dysautonomia is linked to autoimmune processes, sometimes identified by serological markers. These cases can be severe and resistant to typical therapies 17.

Causes of Dysautonomia

Understanding what leads to dysautonomia is essential for both diagnosis and treatment. Causes are diverse, ranging from genetic mutations to acquired injuries and autoimmune reactions.

Cause Type	Example Conditions	Pathophysiology Summary	Source(s)
Genetic	Familial Dysautonomia	IKBKAP gene mutation, neuronal loss	6 7 8 10 11 16
Neurodegenerative	Parkinson’s disease	Loss of autonomic neurons, alpha-synucleinopathy	2
Trauma	TBI-related dysautonomia	Disconnection of ANS pathways	3 13 14 15
Connective Tissue	EDS, Hypermobility Spectrum	Connective tissue laxity affects vessels, neuropathy	1 9 12
Autoimmune	Autoimmune POTS, other	Immune-mediated nerve damage	17
Infectious/Inflammatory	Long-COVID dysautonomia	Post-viral autonomic dysfunction	4 5
Medication/Secondary	Drug-induced dysautonomia	Side effects of medications	12

Table 3: Main Causes of Dysautonomia

Deeper Dive into Causes

Dysautonomia’s origins can be broadly sorted into inherited, acquired, and secondary causes.

Genetic Causes

Familial dysautonomia is caused by mutations in the IKBKAP gene, leading to abnormal splicing and loss of function of the ELP1 protein. This disrupts the development and survival of both sensory and autonomic neurons. The mutation is particularly prevalent in Ashkenazi Jews, due to a founder effect 6 7 8 10 11 16.

Neurodegenerative Causes

Conditions like Parkinson’s disease result in the progressive loss of sympathetic noradrenergic neurons, particularly those innervating the heart. This leads to cardiovascular dysautonomia, which may precede motor symptoms and contribute to non-motor manifestations such as orthostatic hypotension and REM sleep behavior disorder 2.

Traumatic Causes

Severe traumatic brain injury can physically disrupt the neural pathways connecting the brain to the autonomic system, leading to persistent and sometimes severe dysautonomia. Research supports the theory of “disconnection” between central and peripheral ANS centers following injury 3 13.

Connective Tissue and Structural Causes

EDS and hypermobility spectrum disorders involve connective tissue laxity, which can affect the integrity of blood vessels and nerves, predisposing to dysautonomia. Neuropathy and medication use may further exacerbate symptoms 1 9 12.

Autoimmune and Post-Infectious Causes

Some dysautonomia cases, especially POTS, are linked to autoimmune processes, sometimes identifiable by specific antibodies. Viral infections (such as COVID-19) can also trigger dysautonomia, potentially via immune-mediated nerve damage or persistent inflammation 4 5 17.

Medication and Secondary Causes

Certain medications, especially those affecting blood pressure or nervous system function, can induce or worsen dysautonomia symptoms. This is particularly relevant in patients already predisposed due to other conditions 12.

Treatment of Dysautonomia

Management of dysautonomia is often complex and tailored to the underlying cause and predominant symptoms. Treatments may be symptomatic, preventive, or—where possible—disease-modifying.

Treatment Type	Key Examples	Targeted Conditions	Source(s)
Lifestyle Modifications	Increased salt/fluid, compression stockings, exercise	POTS, EDS, Long-COVID	1 4 9 12
Medications	Fludrocortisone, midodrine, beta-blockers, IVIG, gabapentin	POTS, OH, autoimmune dysautonomia, TBI	14 15 17 18
Disease-Modifying	ASOs (antisense oligonucleotides)	Familial Dysautonomia	16
Symptom-Specific	GI agents, botulinum toxin, PDE5 inhibitors, pain meds	PD, FD, EDS, POTS	7 18
Supportive Care	Physical therapy, counseling, pain management	All types	9 12 14

Table 4: Treatment Approaches in Dysautonomia

Navigating Treatment Options

There is no single cure for dysautonomia, but a combination of therapies can often provide meaningful relief.

Lifestyle Modifications

Non-pharmacological measures are the first line for many patients. Increased salt and fluid intake, use of compression stockings, and graduated exercise are recommended for orthostatic intolerance and POTS. Avoiding triggers like heat, large meals, or prolonged standing can also help 1 4 9 12.

Medications

• Orthostatic Hypotension: Fludrocortisone and midodrine are commonly used to improve blood pressure control, especially in neurogenic cases such as Parkinson's disease. Droxidopa is another option 18.
• Beta-Blockers: These may help control tachycardia in POTS.
• Pain and Autonomic Storms: After TBI, medications such as morphine, benzodiazepines, chlorpromazine, propanolol, bromocriptine, and gabapentin have been used. Gabapentin, in particular, may help by reducing abnormal afferent signals 14 15.
• Autoimmune Dysautonomia: For severe, refractory cases with evidence of autoimmunity, intravenous immunoglobulin (IVIG) therapy can result in significant improvement for many patients 17.

Disease-Modifying Therapies

For familial dysautonomia, the mainstay remains symptomatic and preventive care, but promising new approaches—such as antisense oligonucleotides (ASOs) that correct the underlying splicing defect—are in preclinical development and may offer hope for the future 16.

Symptom-Specific Therapies

Many symptoms require targeted interventions:

• Gastrointestinal symptoms: Agents like macrogol, lubiprostone, or botulinum toxin can be used for constipation or GI dysmotility 7 18.
• Urinary symptoms: Anticholinergic medications or botulinum toxin injections help with urgency and incontinence 18.
• Excessive sweating or sialorrhea: Glycopyrrolate or botulinum toxin injections are options 18.
• Erectile dysfunction: Phosphodiesterase type 5 inhibitors (e.g., sildenafil) are effective 18.

Supportive and Preventive Care

Physical therapy, occupational therapy, and psychological support are vital for maintaining function and quality of life. Education and support for patients and families are essential, especially with chronic or genetic forms 9 12 14.

Conclusion

Dysautonomia is a complex, multifaceted group of disorders affecting the autonomic nervous system. Its diagnosis and management require careful attention to the wide variety of symptoms, underlying types, and diverse causes. Treatment is often multidisciplinary and tailored to individual needs, with emerging therapies offering hope for the future.

Key Takeaways:

• Dysautonomia encompasses a wide range of symptoms, most notably orthostatic intolerance, palpitations, blood pressure changes, and fatigue.
• There are multiple types, including familial/genetic, acquired (such as POTS and post-TBI), neurodegenerative, autoimmune, and post-infectious forms.
• Causes range from genetic mutations (especially in familial dysautonomia) to trauma, neurodegeneration, autoimmune processes, and post-viral syndromes.
• Treatment is individualized, involving lifestyle changes, medications, supportive care, and—where available—disease-modifying therapies.
• Ongoing research into the mechanisms and treatments of dysautonomia promises better outcomes for patients in the future.