Postural Tachycardia Syndrome: Physiology for psychology

In this article, we are going to have a look at three main things, 1) The physiology of PoTS, 2) How PoTS is different from anxiety and 3) Some key considerations for clinicians who might find themselves working with people who have PoTS.

An introduction to PoTS

Postural Tachycardia Syndrome (PoTS) is a complex and multifaceted health condition that is most often seen in young females of childbearing age, but it's important to remember that it can still be seen in males and people of any age.

It's estimated that 0.2 per cent to 1 per cent of the population in developed countries are living with PoTS. This might not sound like a lot at first, but if we apply this to the UK population data from 2023, you are looking at 137,366 to 686,830 people who are diagnosed with PoTS in this country. Keep in mind that this prevalence estimate was published in 2019, prior to the Covid-19 pandemic, which has had a significant impact on the rise of PoTS cases.

Understanding PoTS physiology

If we want to get technical, PoTS is diagnosed in an adult if the individual assumes an upright posture and experiences a sustained heart rate increase of 30bpm or more, in conjunction with symptoms of orthostatic intolerance (e.g. dizziness, light-headedness, weakness, and fatigue), while in the absence of persistent low blood pressure. This diagnostic criteria changes to 40bpm when assessing paediatrics.

However, I prefer to think of it like this: PoTS is a form of Dysautonomia, this means that the autonomic nervous system isn't working properly. If the autonomic nervous system isn't working properly, then the automatic functions within the body aren't doing their jobs too well. This is why people with PoTS may present with many, seemingly random, symptoms because there are lots of things going on, keeping in mind that presentations are often unique for each individual.

Why am I even telling you this? Because there is one key point that I want to focus on to help us understand the experiences of those with PoTS, and that is adrenaline. 

Those with PoTS may experience two things of note: 1) they are hypovolaemic (a fancy way of saying that there is low fluid volume in the body), and 2) their blood vessels aren't able to constrict effectively. Both of these things are going to affect the body's ability to pump blood back to the heart and around the body. 

Luckily the brain can sense that this circulation need is not being met and it will get the body to compensate by releasing more adrenaline into the system, to tighten up blood vessels and get the heart beating faster. For some people, roughly 30 per cent of those with PoTS, this compensation won't be enough, and they will faint. For others with PoTS, this may be enough to keep them upright and seemingly functional, but they are now pumped full of adrenaline and having to deal with the side effects involved with being in a state of fight and flight.

PoTS vs. anxiety

Now that we understand that people with PoTS are more likely to experience higher levels of adrenaline in their system, we can look at a common challenge that many of them have faced – the misinterpretation of their PoTS symptoms as anxiety.

Anxiety is a mental health condition where someone's adrenaline levels increase when they are exposed to a stressor that they perceive to be threatening. PoTS is a physiological health condition where someone's adrenaline levels increase when they are exposed to PoTS-related triggers such as orthostatic stress, hot environments, dehydration etc. Are you starting to see how there is room for confusion here? PoTS and anxiety are very different health conditions, but their symptom profiles overlap because they both involve adrenaline, which moves someone into a fight and flight state.

This doesn't mean that someone can't experience both PoTS and anxiety. Maybe they already had anxiety before developing PoTS, or maybe they developed anxiety because they developed PoTS and they're now anxious about fainting in public or anxious about not being able to keep up with daily tasks.

The takeaway here is that there are two different factors at play and that understanding this can help us as clinicians to better understand those living with PoTS, so that we can treat them as a whole person. 

PoTS for the clinician

I'm no psychologist, so you can take this with a grain of salt (unless you have PoTS, then we recommend you take it with 6-10 grams of salt daily), but I would like to share with you some useful considerations when working with people who have PoTS. Why? For us to better understand the PoTSie person of course, and to enhance our abilities to make educated judgements around the tools and skills that we apply in clinical sessions. I'm also not at all implying that we don't already do these things as clinicians, but I have a lot of respect for the complex nature of PoTS and how challenging it can be to comprehend the experiences of those living with the condition.

Consideration 1: The PoTSie person knows their own body better than anyone else. They are living these symptoms 24/7 and can usually tell you a lot about what is going on in their body. Maybe they won't use fancy terms like 'venous return' and 'hypovolaemia', but they know a lot about what's going on. They might know this from feeling their symptoms, from trial and error, past experiences, or they might be incredibly well read up on PoTS. Listening to what the person has to say about their PoTS and/or anxiety can make our jobs as clinicians a lot easier.

Consideration 2: As mentioned earlier, there are lots of reasons that living with PoTS could actually cause anxiety. The person might be worried about fainting, worried about falling and hurting themselves, they might be isolated from friends and family, they may have reduced levels of independence, they might be under financial stress due to their inability to work, and they might have heaps of healthcare appointments that they have to keep up with.

Consideration 3: Grief. They may not have a name for it straight away, but people with PoTS are often grieving the life that they had, they are grieving the things that they are missing out on because of their condition, and they are grieving the future that they thought they would have. This doesn't mean that they can't live valuable and quality lives, but it's likely that things are going to look a bit different to what they expected. Their experience of grief is incredibly valid and it's also a very important clinical consideration.

Consideration 4: People with PoTS might have had poor healthcare experiences in the past. Don't take it personally. It's not uncommon to hear that people with PoTS have had challenging experiences with healthcare professionals who haven't been understanding of how complex PoTS and the experiences of living with PoTS can be. So, understanding, patience and kindness will go a long way when building rapport with someone that has PoTS.

Final thoughts

PoTS is a complex health condition, and presentations can vary from person to person, but understanding how PoTS affects someone physiologically can better help us to understand how it might impact them psychologically. We might be able to help those with PoTS develop tools and strategies to manage one piece of their health puzzle but remembering to see the whole puzzle – the whole person – will go a long way in their care.