• Sarah Schafer, MD

Part 2: Is it POTS? Autonomic mimics

Updated: Sep 18

This page is Part 2 of a 4-part series.

Part 1: Is it POTS? Mimics

Part 2: Is it POTS? Autonomic mimics Part 3: Is it POTS? POTS vs. OH

Part 4: Is it POTS? Debunking myths.


Why I never take standing for granted.

I have postural orthostatic tachycardia syndrome (POTS), a common type of orthostatic intolerance found in Sjogren’s patients. For years, I had no idea why I needed to spend sixteen plus hours a day in bed. I knew that Sjogren’s fatigue could be severe, but that did not explain why standing was so intolerable. In 2009, my symptoms became so extreme that I could no longer drive safely. My heart was racing and I felt on the verge of fainting whenever stood for more than a few minutes. My rheumatologist, internist, and the consulting cardiologist had no idea what was wrong with me. Neither they, nor I, were were familiar with POTS at the time. They did not seem to understand the urgency or severity of my situation. Once a heart problem was ruled out, they dropped the ball. While they did not tell me this, I suspect they assumed I was anxious.

Finding no answers, I turned to the medical literature. Based on my reading, I learned that I had classic POTS symptoms. I designed my own home standing test because there were no standardized recommendations for this in 2009. My standing tests were wildly positive: my heart rate (hr) rose between 40 and 50 beats per minute (bpm) within 10 minutes of standing.

I was able to advocate for treatment after sharing my test results and key journal articles with my doctors. Without these two things, I would have been left undiagnosed and untreated. Clinicians often remain unaware that dysautonomia, including POTS, impacts about half of people with Sjogren’s (50). We often need to be proactive to get diagnosed and treated for POTS and other autonomic disorders. Lifestyle measures and medication are both essential for managing my POTS. While I still do not tolerate standing still for more than ten to fifteen minutes, I can take short bicycle rides and sit up for one-two hours at my desktop computer. This was unthinkable before I started treatment. ~ Sarah Schafer, MD and Sjogren's patient


Diagnostic criteria for the three types of orthostatic intolerance POTS, orthostatic hypotension (OH) and neurocardiogenic syncope (NCS).

What is orthostatic intolerance (OI)? Orthostatic intolerance (OI) is the umbrella term for autonomic disorders that make you feel horrible when you are upright. People with OI usually feel lightheaded, shaky, sweaty, and nauseated after standing for more than a few minutes. Difficulty concentrating is a common complaint. This is likely because with OI, the autonomic nerves controlling blood pressure (bp), heart rate (hr), and blood vessel contraction do not work together as they should to keep the blood flowing to the brain when you stand up.


An important distinction: OI refers to prolonged symptoms caused by autonomic disorders, not short-term, reversible situations such as dehydration or bleeding. See Part 1 of this blog series for non-autonomic mimics.



Diagnostic Criteria for the three types of orthostatic intolerance

Postural orthostatic tachycardia syndrome (POTS) is defined by a heart rate increase of 30 beats per minute (bpm) or more for adults or (or > 40 bpm for 12-19-year-olds) within 10 minutes of standing or using the tilt table test. Blood pressure is usually stable, with some variation, but does not show the rapid drop seen with orthostatic hypotension. Some people with POTS will have their blood pressure increase with standing. This can be seen with hyperadrenergic POTS.


Orthostatic hypotension (OH) is defined by a sustained drop in blood pressure, at least 20 mm systolic or 10 mm diastolic within three minutes of standing still or a tilt table test.


If you have OH, you do not have POTS, although the symptoms are similar. Like POTS, the heart rate (hr) increases with standing in people with OH. Increased heart rate is a normal physiologic response to falling blood pressure. The management of OH and POTS are similar, although medication options differ.


This article reviews both acute OH and long-term OH. On Sjogren’s Advocate, OH refers to the long-term problem maintaining blood pressure when upright because of an autonomic nervous system problem. You may share the article with your clinician but be sure to emphasize the chronic nature of your condition.


Neurocardiogenic syncope (NCS), aka vasovagal syncope or “fainting”, is a temporary loss of consciousness caused by a sudden fall in blood pressure and heart rate when upright. It often follows pre-syncopal symptoms such as lightheadedness, nausea, sweating, and pallor (more evident in people with lighter pigmentation). NCS may occur with POTS and OH, but more often occurs alone.



A good evaluation for orthostatic intolerance will look for a variety of causes, both autonomic (especially POTS and OH), and non-autonomic. Clinicians may need some nudging as well as resources such as peer reviewed journal articles to help them know what an autonomic evaluation entails. Be sure to read the POTS page to learn about standing tests that can be done at home and in the clinic. The POTS page and the Dysautonomia/POTS resource page offer printouts for sharing with clinicians. It is also a good idea to review the Clinician Handouts page as a remainder of how to use education materials effectively. It is rarely a good idea to print out and share Sjogren's Advocate webpages or blog posts with your clinician. Read here why this can backfire.

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