Underlying Causes

welcome to vagusDysfunction of the vagus nerve almost always occurs as a consequence of a significant, albeit often un-noticed bodily change, an illness, a physical trauma, a deficiency or toxic exposure.
Thus, most cases might be considered Secondary Dysautonomia.

However, there are some underlying etiologies that might be considered Primary Dysautonomia.
These might include genetic defects in the components of the autonomic nervous system or the rennin-angiotensin system.
For example, there is a known defect in the norepinephrine transporter protein that leads to severe dysautonomia. Developmental Dysautonomia might be the term best to describe those that onset with normal growth spurts and menarche.

The Healthy Body In Homeostasis and Harmony


Its important to recognize that the long list of symptoms are secondary consequences following a primary event. Its often useful to use the analogy of the healthy body being like a smooth surface of a pond. Something is dropped into the system that disturbs it, that causes a ’ker-plunk’. Then the ripples follow on the surface. Just about any systemic illness or trauma can be that ker-plunk and an endless list of inciting causes have been implicated. The most common causes in my experience are concussions, mononucleosis, growth spurts, menarche, Ehlers-Danlos syndrome, drug toxicity, thyroid dysfunction and diabetes.



  • Growth Spurt
  • Menarche
  • Excessive Exercise
  • Deconditioning, prolonged bed confinement
  • Anxiety (?)


  • Concussion
  • Sinus Surgery
  • Chiari Malformation


  • Mononucleosis
  • Other viral illnesses
  • Lymes disease, RMSF, Q Fever
  • Pneumonia


  • Thyroid disorders
  • Diabetes
  • Pheochromocytoma
  • Estrogen/Progesterone imbalance, pregnancy


  • Celiac Disease
  • Nutritional Deficiencies
  • Food Allergies

Autoimmune illnesses

  • Lupus
  • Voltage-gated potassium channel (VGKC)
  • AAb
  • Ganglionic Acetylcholine Receptor AAb
  • Mast Cell Activation Disorders


  • Ehlers-Danlos Syndrome
  • Norepinephrine Transporter defects



  • Dizziness/Light-headedness Near-Syncope
  • Syncope
  • Decreased/Blackout tunnel Vision Foggy Thinking/ Attention Deficit Anxiety/Panicky
  • Migraine Headaches
  • Facial Pain
  • Neck Pain/”Coat Hangar Pain” Insomnia
  • Mood Disturbances/Depression


  • Palpitations
  • Racing Heart
  • Increased heart rate when lying down Chest Discomfort/Pain
  • Shortness of Breath
  • Hyperventilation symptoms


  • Nausea
  • Abdominal Pain
  • Digestion Issues
  • Urinary frequency/incontinence


  • Acral coldness or Pain/Raynaud’s Excessive Sweating Palms and Soles Joint Pains
  • Foot swelling and blood pooling in legs


  • Fatigue
  • Orthostatic Intolerance Tremulousness/Shakiness
  • Weakness
  • Exercise Intolerance
  • Feeling Hot or Cold while others fine Excessive sweating
  • Anhydrosis

Of note, in my practice I have cared for a few girls who were perfectly healthy until the day they head-butted a soccer ball or took a soccer ball to the head a little harder than usual. Another developed severe dysautonomia following a softball strike to the head. None of these led to seeking medical attention for the primary events. While it is critical to seek out the ker-plunk as its correction is tantamount to treating dysautonomia, it should be noted that often times the ker-plunk may be in the past and done with (for example the residual effect long after mononucleosis or after a mild concussion).

Developmental Dysautonomia

Dysautonomia seems to commonly occur as part of the course of normal growth and development. Indeed, something very strange starts happening with the vagus nerve in many healthy people around the age of 9 and continues through late adolescence. About that time, the vagus nerve stops controlling heart rate and blood vessel diameter well. Perhaps this is because rapid gains in height occur during this age and the vagus nerve has trouble adjusting its input to accommodate the new height. In addition, the blood vessels of an adolescent are extremely healthy and able to dilate very well. The combination of these two factors results in a person who develops vasovagal symptoms very easily under a variety of circumstances. Indeed, this can become even more pronounced in extremely athletic young people. Atheletic conditioning increases vagal tone naturally and also increases vascular compliance (makes ‘the tank’ more capable of stretching to new sizes quickly).

understanding thisUnderstanding this, its easy to see why much of autonomic dysfunction might be thought of as “an affliction of too much health”

Understanding this, its easy to see why much of autonomic dysfunction might be thought of as “an affliction of too much health” in that it’s the result of having such healthy and easily distensible arteries and a very active vagus nerve. Having said that, it’s a problem sometimes too of not treating well the “high performance machine” that is a healthy young body. This will be discussed later. In some of these people, however, the autonomic nervous system becomes so dysfunctional that it is quite debilitating and that is when its sometimes called POTS. For these folks, the question of an underlying predisposing set of factors always arises, such as a defect in the norepineprhine transporter, making their secondary or developmental dysautonomia really just the tipping point of an underlying Primary Dysautonomia.

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