The autonomic nervous system controls automatic, unconscious functions—things your brain doesn’t need to actively think about to control. For example, the autonomic nervous system controls bodily functions like blood pressure and heart rate, sweating, digestion, and breathing.
Dysautonomia is the dysfunction of the autonomic nervous system. “Dysautonomia” is a broad term that can encompass multiple conditions. It occurs when the functions that your body handles automatically stop operating very well on autopilot.
There are no good estimates for the number of people who are affected since “dysautonomia” can be many things. However, some specific types of dysautonomia are a little easier to recognize. For example, orthostatic hypotension is the second most common cause of fainting, occurring in 15% of all patients who experience fainting episodes. Postural orthostatic tachycardia syndrome (POTS) occurs in about 0.2% of the general population. About 75% of POTS patients are female.
Due to a lack of awareness and because it is not well-understood, getting a diagnosis can take years for some patients.
Common symptoms of autonomic dysfunction can include abnormal heart rate, lightheadedness, fainting, digestion issues, or irregular kidney function.
A more exhaustive list of symptoms that some patients may or may not experience:
It depends on the type of dysautonomia to be identified, but let’s talk about two common forms: neurocardiogenic syncope and postural orthostatic tachycardia syndrome (POTS).
Your doctor will suggest an electrocardiogram, or “ECG”, over a longer period of time to identify a period of clinical syncope. This will not always accurately identify some types of dysautonomia, however. Sometimes, clinicians will recommend tilt-table tests, which may more clearly determine if the type of dysautonomia is POTS or some other cause. Tilt-table tests involve literally tilting a patient in different positions to see if it causes symptoms.
There currently is no cure for dysautonomia but patients’ symptoms can be managed to improve their quality of life.
Rarely, dysautonomia can occur secondary to other, underlying conditions like Chiari malformation, Ehlers-Danlos syndrome (EDS), and mast cell activation syndrome (MCAS). Because of this, it is sometimes possible to improve a patients’ dysautonomia symptoms by treating the underlying condition that is causing them. That is why it is so important to get a good work-up by your clinician!
For a good POTS explainer, the following publications were used to help develop this page and are available open-source online:
Other sources include:
Reviewed on 7/2021