Dysautonomia: Understanding Autonomic Dysfunction

What is Dysautonomia?

Autonomic Dysfunction

Dysautonomia is a blanket term for any malfunctioning of the autonomic nervous system. The autonomic nervous system controls all of the functions that happen in your body without your control, such as breathing, your heart beating, digestion, etc. When there is autonomic dysfunction – or dysautonomia – the autonomic nervous system sends the wrong signals to organ systems, or no signals at all. This results in irregular heartbeat, respiratory difficulties, and improper digestion.


Almost every autonomic function is controlled by the vagus nerve, a long nerve that runs down the back and sides of the neck. If there is damage to the vagus nerve, either from injury or surgery, it can result in dysautonomia. Dysautonomia can be familial, meaning it runs in your family. Sometimes it occurs randomly during the teenage years and then disappears when someone enters adulthood. Dysautonomia may also be brought on by severe bacterial or viral infections such as Epstein-Barr or meningitis. However, most cases of dysautonomia stem from underlying conditions including, but not limited to, the following:

  • Ehlers Danlos Syndrome
  • Craniocervical Instability
  • Chiari Malformation
  • Diabetes
  • Lyme Disease
  • Autoimmune Diseases


Types of Dysautonomia

Since the autonomic nervous system controls all of the systems in the body, dysautonomia can manifest itself in various ways. There are several different types of dysautonomia, categorized by the system of the body that they affect and the symptoms they produce. While there are numerous forms of dysautonomia, the three main types are POTS, neurocardiogenic syncope and gastroparesis.

POTS (Postural Orthostatic Tachycardia Syndrome)

Postural orthostatic tachycardia syndrome, also known as POTS, is when the body is unable to properly adjust to being in an upright position. When a patient goes from lying or sitting down to standing up, their blood pressure drops and their heart rate increases. Rather than blood moving throughout the body normally, it pools in the lower extremities, resulting in reduced blood flow to the heart. Reduced blood flow to the heart results in a rapid heart rate that is resolved when the patient returns to a supine position.

Neurocardiogenic Syncope

Neurocardiogenic syncope is the most common cause of fainting. Also called vasovagal syncope, this type of dysautonomia occurs when blood pressure suddenly and rapidly drops, resulting in reduced blood flow to the brain. When blood flow to the brain is reduced, the patient loses consciousness for several seconds and faints until blood pressure returns to normal. This drop in blood pressure is brought on by any sort of strain to the body, such as prolonged standing, heavy lifting, or excessive heat exposure.


Gastroparesis is a slowing or partial paralysis of the stomach. In a normal patient, the stomach moves food into the small intestine for digestion. In gastroparesis, the stomach muscles fail to move the food and it remains there without being properly digested. In some gastroparesis patients there is paralysis in the intestines, which prevents food from being properly digested and nutrients from being properly absorbed.

Chiari Malformation


Since there are various types of dysautonomia that can affect numerous systems in the body, symptoms are incredibly wide-ranging.

  • Tachycardia
  • Bradycardia
  • Heart Palpitations
  • Hypotension
  • Orthostatic Intolerance – Hypotension and Tachycardia Upon Standing
  • Nausea
  • Vomiting
  • Constipation
  • Bloating
  • Bladder Dysfunction
  • Dizziness
  • Brain Fog
  • Memory Problems
  • Blurry Vision
  • Heat/Cold Intolerance
  • Excessive Sweating
  • Headaches
  • Muscle and Joint Pain
  • Incontinence
  • Fatigue
  • Noise Sensitivity


Dysautonomia testing

A tilt table test can be used to assess how a patient responds to being in an upright position. This is typically used to diagnose Postural Orthostatic Tachycardia Syndrome.

Diagnosis of dysautonomia depends on the suspected type. For instance, if POTS is suspected testing might include a tilt table test. A tilt table test consists of the patient being strapped to a table, initially lying flat, and then transitioned into an upright position. The patient’s blood pressure and heart rate is then noted to see the variation between supine and upright position.

Neurocardiogenic syncope can typically be diagnosed based on patient’s symptoms. If a patient reports frequent incidents of fainting, neurocardiogenic syncope may be suspected. An MRI of the brain should be done to check for neurological conditions, as well as a full cardiac workup to check that heart function is okay. If all else is ruled out, it increases the likelihood of neurocardiogenic syncope.

To diagnosis gastroparesis there are multiple tests that can be done. Gastric emptying scans can determine how long it takes the stomach to empty food that is ingested. Various blood tests may be done to evaluate how well nutrients are being absorbed in the patient. Imaging like x-rays and MRIs should also be done to rule out any structural problems in the digestive tract like blockages or tumors.


Treating dysautonomia depends on the type of autonomic dysfunction the patient has. This determines the type of specialist the patient needs to see for treatment. For instance, POTS is typically treated by a cardiologist or an electrophysiologist. POTS patients may also want to work with a neurologist in addition to a cardiac doctor. Treatment will typically consist of medications to lower heart rate and increase blood pressure. Additional treatment would be certain lifestyle changes, such as wearing compression stockings and increasing salt and fluid intake to boost blood pressure.

A neurologist and cardiologist may be used to treat patients with neurocardiogenic syncope. The treatment of neurocardiogenic syncope would consist of lifestyle changes, such as avoiding things that trigger fainting. A patient may also take medication to increase blood pressure or wear compression stockings to prevent blood from pooling in the lower extremities.

A gastroenterologist and neurologist may be used to treat gastroparesis. Treatment options include lifestyle changes, such as eating smaller meals and foods that are easier to digest. Medications to aid digestion may also be taken. In severe cases, a feeding tube may be needed to provide the patient with nutrition.


, , , , ,

No comments yet.

Leave a Reply