EDS and POTS
Many patients with hypermobility spectrum disorder (HSD) and hypermobile EDS (hEDS) either have symptoms of or have been diagnosed with “POTS” or “dysautonomia”. It is estimated that up to 70% of HSD/hEDS patients report symptoms consistent with dysautonomia and up to 40% meet diagnostic criteria for POTS. The purpose of this post is to provide a brief overview of the answers to the following questions:
What are POTS and dysautonomia? What about orthostatic intolerance?
How are POTS and orthostatic intolerance diagnosed?
- What are POTS and dysautonomia? What about orthostatic intolerance?
There are many great explanations out there, including this video Mayo Clinic Minute: What is POTS? , but let’s explain this a little further now. When discussing dysautonomia, what we are usually referring to are POTS (postural orthostatic tachycardia syndrome) and orthostatic intolerance. Dysautonomia is an umbrella term that refers to dysfunction of the autonomic nervous system (ANS). There are serious forms of autonomic dysfunction that progress over time and are typically seen in the elderly; we will not focus on these. Instead, we will discuss the types almost always seen in HSD/hEDS; fortunately, these are the types that usually get better.
To understand dysautonomia, it is important to understand what the ANS does. Simply stated, the ANS is the part of the nervous system that does all the automatic things throughout the day that we do not think about, or things that are involuntary. It is like a “thermostat” that regulates various bodily functions in response to changes in the body and the environment. These include regulation of blood pressure when you stand up, heart rate when you try to run, sweating when you step outside in the heat, movement of food through the bowels after you eat, etc. The ANS communicates through chemical messengers, the most common of which is the stress hormone, adrenaline.
In patients with dysautonomia, the normal reflexes of the ANS are thrown off balance. The most common form of dysautonomia is called “orthostatic intolerance”, in which patients have difficulty tolerating the upright position. Common symptoms are dizziness, palpitations and exercise intolerance. Symptoms are typically brought on by the upright position and relieved when laying down. Other symptoms that may or not be related to upright posture can include, but not limited to, shortness of breath, chest pain, chronic fatigue, generalized weakness, heat intolerance, headaches, brain fog, muscle and joint pain, nausea, abdominal pain, and abnormal sweating.
POTS describes a subset of patients with orthostatic intolerance. In addition to the above-mentioned symptoms, these patients typically have an excessive elevation in heart rate when in the upright position. Both orthostatic intolerance and POTS are dysautonomias that are generally managed in a similar way.
- How are POTS and orthostatic intolerance diagnosed?
The diagnosis of POTS is based on 3 main criteria. The first one is the presence of characteristic symptoms, as discussed above, for at least 6 months. The second is objective evidence of an exaggerated heart rate response with upright posture. Ideally this is done with a tilt-table test. There are different heart rate cut-offs depending on age. The third criteria is exclusion of other conditions that can mimic POTS.
As mentioned before, a patient can have characteristic symptoms without meeting the heart rate criteria. In this situation, the patient does not have a diagnosis of POTS, but can still have orthostatic intolerance.
Many patients have been seen at Mayo Clinic for issues related to POTS. See the video here for Katie’s experience: Katie's Experience
Stay tuned for the next post on this topic, where we will cover the best treatment strategies for POTS.
Author: Daniel Dudenkov, MD