There are many forms of dysautonomia that can occur at any age: pediatric, adult, and/or geriatric.  These autonomic nervous system disorders usually involve abnormal symptoms in many organs systems including cardiac, gastrointestinal, neurological, pulmonary, as well as others.  Dysautonomias can range from mild to disabling and may or may not be neurodegenerative.  (Since there are many forms of dysautonomia we use the singular term “dysautonomia” to reference autonomic disorders in general or when referring to a specific condition such as “orthostatic hypotension.”  We use “dysautonomias,” plural, when referring to many disorders of the autonomic nervous system.)

Pediatric:  Also known as genetic or hereditary dysautonomias, these conditions often reflect problems or mutations which occur during the development of the autonomic nervous system.  One type of mutation, found almost exclusively in people of Ashkenazi Jewish heritage, affects the autonomic and sensory nervous system development causing familial dysautonomia.  Another mutation causes an increased level of phenylalanine (Phe) in the bloodstream causing a metabolic disorder called phenylketonuria (PKU).  Another mutation in the ATP7A gene that is responsible for transporting copper throughout the body causes  “kinky hair” and is known as Menkes disease.  In Hirschsprung’s disease there is a lack of development of nerve cells in the enteric nervous system.  Other pediatric dysautonomias include:  hereditary sensory and autonomic neuropathy (HSAN), congenital central hypoventilation syndrome (CCHS), and catecholaminergic polymorphic ventricular tachycardia (CPVT).  In general, dysautonomias in early childhood are rare.  

Teen/Adult Onset:  In teens and adults, dysautonomias usually reflect functional changes in a generally intact autonomic nervous system.  Dysautonomias in adults often are associated with, and may be secondary to, another disease process or a drug.  Common secondary causes include medications, chemotherapy, radiation treatments, spinal cord or head injury, or diabetes (such as diabetic autonomic neuropathy).  Less commonly the body’s immune system mistakenly attacks and damages certain parts of the autonomic nervous system in autoimmune autonomic ganglionopathy.

The most common forms of adult onset dysautonomia are:

Autonomically Mediated Syncope Also called vasovagal syncope, neurally mediated syncope or neurocardiogenic syncope, individuals with autonomically mediated syncope suffer from frequent episodes of fainting or near fainting where the blood pressure drops by 20 mmHg systolic/ 10 mmHg diastolic with upright posture.  Most patients have symptoms with little change in heart rate.  In some cases the drop in blood pressure occurs as a compensatory function following tachycardia, as seen in POTS, or bradycardia can precede a drop in blood pressure.  

Postural Orthostatic Tachycardia Syndrome (POTS) POTS is the most common dysautonomia and is characterized by symptoms in multiple organ systems and an abnormal increase in heart rate (30 bpm in adults, 40 bpm in teens) upon standing.  POTS is a common but underrecognized health condition affecting an estimated 1 in 100 teenagers and, in the United States, as many as 3 million adult and teen patients combined.  POTS is a dysfunction of the autonomic nervous system that involves abnormal symptoms in many parts of the body, including abnormal blood flow to the heart, lungs and brain.  It often involves problems with digestion, temperature regulation, and many other involuntary functions of the body.  Because the condition involves the autonomic nervous system, which regulates mostly internal functions, it is commonly known as an “invisible illness.”

Geriatric:  In the elderly, dysautonomia typically reflects a neurodegenerative disease.  The degeneration may be in the form of lesions in the central nervous system, as in multiple system atrophy (MSA), or in loss of autonomic nerves not involving the central nervous system, as in pure autonomic failure (PAF).  Most geriatric cases involve damage to nerves that results in loss of autonomic reflexes, also known as autonomic failure.  It is common in geriatric patients to experience some orthostatic hypotension which is characterized by a drop in blood pressure upon standing.  Neurogenic orthostatic hypotension is a neurodegenerative form of dysautonomia in which the autonomic system loses the ability to properly regulate blood pressure as one moves from sitting or lying down to standing.

Primary, Secondary or Idiopathic?

Regardless of when a dysautonomia occurs in life, these disorders can be primary, secondary, or idiopathic.  A primary dysautonomia is when we know autonomic dysfunction is the main disease process.   Examples of primary dysautonomias include familial dysautonomia, multiple system atrophy, pure autonomic failure, and some forms of syncope among others.  Secondary dysautonomias are experienced as a consequence of another disease process, as in autonomic neuropathy associated with diabetes or POTS as a result of an auto-immune disease.  Idiopathic dysautonomias are autonomic nervous system disorders where the main disease process is unknown.  The pathophysiology of most dysautonomias is complex and not well known therefore it is helpful to discuss with your doctor if your dysautonomia is a primary, secondary, or idiopathic disorder.   

Coexisting Conditions?

Since dysautonomia patients experience many symptoms from multiple organ systems it is helpful to consider the possibility of underlying causes or coexisting conditions.  Here is a sample list of common coexisting conditions associated with dysautonomias.