POTS or Anxiety? How to Tell the Difference

All right, so what do you do when you're told that your POTS symptoms are from anxiety? I think this is a really important question. It's important because every year loads of people that have POTS are diagnosed with anxiety, and a lot of times it's given kind of as a brush-off diagnosis — like "I don't know what else to do with you." And that's a big deal because a lot of people with POTS may have anxiety, but it doesn't mean that that is the cause of what's going on.

If you do have anxiety that causes POTS, dealing with anxiety is magic for those people. But if that's not the cause, then that's not going to get you to the solution. So that's really important to me when I think about people that have POTS — like what is happening within their body, and like the fact that they get scared about that. It makes sense to me that they would feel anxious. Like, your body is freaking out. It's reasonable that some anxiety might come from that. But we have to be able to differentiate which of those is the case.

How We Look for Evidence

So the next logical question is: how do we do that? How do we match the problem to the plan? And the way we do that is we look for evidence. We look for evidence that would support anxiety being the cause, or physiology being the cause.

1. Does Changing a Behavior Reduce Your Symptoms?

So if you can change your breathing, if you can change your self-talk, if you can use an anxiety medication — and these change your behaviors of anxiety and your POTS symptoms go away — then there might be some evidence there that anxiety is the main problem. But if we find that those things don't completely solve the problem, then there may be an element of physiology that we have to dig deeper into to be able to solve for that.

2. Which Comes First?

Is it that the anxiety comes first — "I feel anxious and then I have symptoms" — or do I start to have symptoms as my physiology changes, and then I get anxious about that? Because it's reasonable, right? "Oh no, here it comes again." That can induce its own anxiety. That can perpetuate the problem and make it even worse. But the real cue is which happens first. Is the anxiety first, or does the change in physiology happen first?

If the anxiety comes first, we treat the anxiety. If the change in physiology comes first, then we treat the change in physiology.

3. We Measure It

So that's where kind of more advanced autonomic testing comes in, where we look at orthostatic changes — what happens when we move you through different positions — and then we look at how does that pair with neurological function. A lot of times what we see are actually brain breakdowns within these integrated reflexes within the brain and brainstem areas — which is why understanding how the brain controls the autonomic system matters so much — and that causes the change in physiology that ultimately leads down the road toward anxiety or toward symptoms.

So we can actually look for: do errors occur in the system, in the physiology, that are independent of anxiety? So if we do other things that create context that aren't anxiety, do we see errors in that system? And if we do, we're looking for these little patterns that help us point to where in the brain we're having a breakdown, and we solve for those patterns.

The Running Track Story

A couple years ago I actually had a conversation with an attorney. I was there to give a deposition, and the deposition was about a brain injury case where that person had experienced tachycardia afterwards. And their position was like, "This is psychosomatic. It's all in her head. How can you tell me that the tachycardia she experiences is from a brain injury? It's just anxiety. It's all in her head."

And I said, "OK, yeah, I get that. I get where you would think that." So I just asked, "OK, if I asked you to run a lap around a track — 400 meters, fast as you can — and when you got done I would give you a million dollars if you could bring your heart rate back down to normal within 10 seconds, what would you do? You think you could do it?"

And he laughed. He's like, "No, I can't do that." I was like, "Yeah, of course. Because this is a normal reflex. It's related to metabolic output." If you increase metabolic output from muscles and cells, you have to bring more oxygen to them, you have to bring more blood flow, and your heart rate is one of the tools that you have that helps you to be able to do that, right?

So if you have a brain injury — or any probability that you could interrupt the way that blood circulates in your body, or even the way that your brain perceives blood circulating in the body — your heart could adapt by beating faster to try to push more blood flow into the system. That can be an example of where we have evidence that the tachycardia may be from something different. That's not just purely anxiety.

A Case That Shows How This Works

Let me tell you a story that will kind of help solidify this. So we had a woman, she's 46 years old, and she came in because in the last three months she had been experiencing a relapse of what she called seizures that she hadn't experienced for 11 years prior to that. And what her seizures kind of look like are like syncope — where she's passing out. And again, she went 11 years without having one, and then three months ago they start again and they're accelerating in frequency. So trying to figure out, OK, what's going on here, what do I do about this.

So we do kind of a series of tests. Two of the tests that we do in a row are a Valsalva test — where we increase the pressure in your chest like this — and we see how your blood pressure, your cerebral blood flow, your breathing, how all those things respond to that change in pressure. And then we kind of take a break, and then we do another test where we bring you up from zero degrees to 70 degrees on a table — a tilt table test — and we do that same thing. So we're measuring like, how does your body deal with changes from going from laying down to standing up.

What the Numbers Showed

What we found with her was that we measured the cerebral blood flow — blood flow to the brain — but then we also look at the air that she breathes out. And that's really important because the amount of carbon dioxide that's concentrated in the air that she breathes is going to give us a signal for how much carbon dioxide is in blood vessels, in our blood. And the vessels in your brain react to how much carbon dioxide is in the system. So if there's a lot of carbon dioxide, they dilate and it flushes it out. If there's little or low levels of carbon dioxide, the blood vessels actually constrict, which reduces blood flow to the brain — which can cause neurological symptoms, right?

So what we found was, after she did the Valsalva, her numbers on the carbon dioxide dropped. Normally we like to keep them over 35. Hers actually were resting at about 34, but they dropped to 18 to 21, and they kind of held down there for a while. And then we moved into the tilt test from there, and it wasn't fully recovered. And what we found was that level maintained, but the blood flow to her brain when she went up dropped almost in half within the first minute of being at 70 degrees.

At that point, after that physiological change happened, her breathing rate went up. So she actually started to hyperventilate because she was starting to feel lightheaded — like she was going to have a seizure. So she was scared that she was going to have a seizure, her breathing changed, which further dropped carbon dioxide levels. She felt like she was going to fall over, and we actually had to stop the test in under two minutes. Which is really, really short. We usually go at least a 10-minute period of time, and we work really hard to make sure that people push through and stay on target there.

So what's interesting about that is we see hyperventilation, which can cause decreased carbon dioxide levels. But the carbon dioxide was already low before she started to hyperventilate. So we were able to look at that and kind of peel it apart and figure out where we could make changes in the way that she was sensing pressure.

The Results a Month Later

When we did that, we came back and retested it a month later. So figured out what the problem was, we made a plan, we executed the plan, and then we sent her home. We sent her home to do a version of those exercises at home, and then we brought her back a month later and we retested everything.

And when we retested everything, found that the Valsalva didn't induce that big drop in carbon dioxide ratio, and it didn't induce a big drop in cerebral blood flow. And she was actually able to do the full tilt test fine. The lowest that her numbers dropped were to 88% of her resting level. To give you some context — we don't like to see them drop below 90 in the first minute or under 80 overall, and she was well above that — 88% throughout the whole test. Which is great. It's fantastic.

But even more important than that was like she had known over the last month she didn't have any seizure or syncopal events. She felt calmer. She was able to deal with stress better. And she was less reactive. So overall she was doing better. But these symptoms all kind of looked like anxiety, but they were really wrapped in a wrapper of physiology.

So it's really helpful to be able to actually measure them, peel it all apart, see where the deficits lie within that system — because then you're not as sensitive to the things that make you anxious, and you have the benefit of not having the symptoms that create the anxiety.

The Recap

So we're looking for evidence. We're looking for evidence of whether or not anxiety is causing the change in physiology, or the physiology is causing anxiety.

• Number one: We look to see if there's a behavior — something that you can change through your own volition — that will reduce the amount of symptoms that you have. If so, we may need to look at anxiety as the cause. If not, then we may need to dive deeper and measure the physiology.
• Number two: We look at which comes first. Does anxiety lead to the change in physiology and the symptoms? Or does the physiology cause the anxiety — like we just saw in the case we talked about?
• Number three: We measure it. We actually measure and make sure all the reflexes that have to be in place to execute this system work. So I should be able to stand up and have all of these things work — no problem, no symptoms. If not, we need to figure out why. When I stand up, where is this thing breaking down, and how do we solve that problem so it doesn't make me anxious?

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