Dysautonomia: Understanding Just How Big the Umbrella Really Is

When many people hear the word dysautonomia, they immediately think of POTS. While Postural Orthostatic Tachycardia Syndrome (POTS) is one of the better-known forms of dysautonomia, it represents only one part of a much larger and more complicated picture.

Dysautonomia is an umbrella term used to describe disorders involving dysfunction of the autonomic nervous system (ANS).

The autonomic nervous system controls many of the things our bodies are supposed to do automatically—without us ever having to think about them.

This includes:

• Heart rate and blood pressure

• Blood vessel constriction and circulation

• Body temperature and sweating

• Digestion and intestinal movement

• Bladder function

• Breathing patterns

• Pupil responses

• Sexual function

• The body's response to standing, exercise, heat, stress, and other environmental changes

When this system does not regulate the body appropriately, symptoms can appear throughout multiple organ systems. That is one reason dysautonomia can be so difficult to recognize.

Dysautonomia Is Not Just One Disease

One of the most important things to understand is that dysautonomia is not a single diagnosis with a single set of symptoms.

It is a broad category of disorders involving abnormal autonomic nervous system function. Some forms primarily affect heart rate and blood pressure. Others can affect sweating, digestion, temperature regulation, bladder function, or several systems simultaneously.

Symptoms can also range from relatively mild to profoundly disabling.

A person living with dysautonomia may experience dizziness, fainting or near-fainting, rapid heart rate, unusual changes in blood pressure, severe fatigue, exercise intolerance, headaches, nausea, digestive problems, temperature intolerance, abnormal sweating, brain fog, weakness, tremulousness, sleep disturbances, and many other symptoms.

Not every person experiences the same symptoms, and symptoms may fluctuate significantly from one day to another.

Some of the Conditions Under the Dysautonomia Umbrella

Postural Orthostatic Tachycardia Syndrome (POTS)

POTS is one of the most recognized forms of dysautonomia. It involves an excessive increase in heart rate after moving into an upright position, along with chronic orthostatic symptoms.

People with POTS may experience lightheadedness, palpitations, shakiness, fatigue, exercise intolerance, brain fog, nausea, weakness, and sometimes fainting.

Importantly, POTS itself is heterogeneous. Different underlying mechanisms and associated conditions may contribute to a person's symptoms.

Neurocardiogenic or Vasovagal Syncope

Vasovagal syncope is a common cause of fainting. An abnormal autonomic reflex can cause blood pressure and/or heart rate to fall, temporarily reducing blood flow to the brain.

Before fainting, someone may experience nausea, sweating, warmth, tunnel vision, dizziness, or weakness.

Orthostatic Hypotension

Orthostatic hypotension occurs when blood pressure falls significantly after standing.

Normally, the autonomic nervous system quickly adjusts blood vessel tone and heart function to maintain adequate blood flow when we change positions. When that response does not work properly, standing can cause dizziness, weakness, blurred vision, confusion, or fainting.

Neurogenic Orthostatic Hypotension

Neurogenic orthostatic hypotension is a particular form of orthostatic hypotension caused by impaired autonomic nervous system signaling.

It may occur with certain neurologic or autonomic disorders and differs from low blood pressure caused by factors such as dehydration or medications.

Multiple System Atrophy

Multiple system atrophy (MSA) is a rare, progressive neurologic disorder that can cause significant autonomic dysfunction in addition to problems with movement, balance, and coordination.

Autonomic symptoms can include severe orthostatic hypotension, bladder dysfunction, sexual dysfunction, and abnormal sweating.

Pure Autonomic Failure

Pure autonomic failure is another rare disorder involving degeneration of parts of the autonomic nervous system. It commonly causes neurogenic orthostatic hypotension and may also affect sweating, bladder function, and other automatic body processes.

Autoimmune Autonomic Ganglionopathy

Autoimmune autonomic ganglionopathy (AAG) is a rare condition in which the immune system interferes with communication within the autonomic nervous system.

It can cause widespread autonomic symptoms, including severe orthostatic hypotension, gastrointestinal problems, abnormal sweating, dry eyes or mouth, urinary difficulties, and impaired pupil responses.

Dysautonomia Can Also Be Secondary to Other Conditions

Another reason the dysautonomia umbrella is so large is that autonomic dysfunction can occur alongside or as a consequence of another medical condition.

Examples include certain autoimmune diseases, diabetes and other causes of autonomic neuropathy, neurologic disorders, infections, and some genetic or connective-tissue conditions.

One association that has received increasing attention is between POTS and hypermobility disorders, including hypermobile Ehlers-Danlos syndrome (hEDS).

Ehlers-Danlos syndromes are inherited connective-tissue disorders, and they are not themselves forms of dysautonomia. However, autonomic symptoms—particularly orthostatic intolerance and POTS—are reported frequently in people with hypermobility-related disorders.

This distinction matters. Two conditions can overlap or commonly occur together without being the same disease.

More Than What You Can See

Perhaps one of the hardest things about dysautonomia is that much of it is invisible.

Someone can look completely healthy while their body is working extraordinarily hard simply to remain upright.

A trip to the grocery store, standing through a shower, sitting through school, walking across a parking lot, spending time outside in the heat, or participating in activities that seem effortless to others may require enormous physical effort.

Symptoms can also change. A person may have a relatively good morning and struggle tremendously that afternoon. They may participate in an activity one day and be unable to repeat it the next.

That variability does not make the illness less real.

Why Awareness Matters

Because dysautonomia can involve so many different systems, patients may see multiple specialists before the pieces of their symptoms are connected.

A racing heart may lead to cardiology. Stomach problems may lead to gastroenterology. Headaches may lead to neurology. Fatigue may prompt laboratory testing. Fainting may lead to emergency evaluations.

Each symptom may be investigated individually without immediately recognizing that autonomic dysfunction could be contributing to several of them.

Greater awareness does not mean assuming every unexplained symptom is dysautonomia. It means understanding that the autonomic nervous system reaches nearly every part of the body, and dysfunction within it can produce complex, multisystem symptoms that deserve thoughtful evaluation.

The Umbrella Is Bigger Than Most People Realize

Dysautonomia is POTS—but it is not only POTS.

It can involve disorders of heart rate, blood pressure, circulation, digestion, sweating, temperature regulation, bladder function, and other processes most of us never have to consciously think about.

And for many individuals, dysautonomia exists alongside another condition, creating an even more complicated medical picture.

The more we understand the size of this umbrella, the better equipped we are to recognize symptoms, support patients and families, encourage appropriate medical evaluation, and advocate for continued research.

Most importantly, we can learn to listen when someone tells us that something is wrong—even when we cannot see it.

Awareness creates understanding. Understanding creates compassion. And compassion can change the experience of living with an invisible illness.