What’s POTS? Why Your Heart Races When Standing

I talk so much about Postural Orthostatic Tachycardia Syndrome (POTS) on this blog, but I haven’t yet dedicated a post to explaining what this syndrome is. Maybe you’ve just received a diagnosis, or maybe you’re asking yourself why your heart races when standing all of a sudden. Or perhaps you are a caretaker for someone with suspected or diagnosed POTS. Whatever your story may be, I bet you’re itching to learn more about this common, yet vastly under-diagnosed syndrome. 

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What Exactly Is Postural Orthostatic Tachycardia Syndrome, or POTS?

POTS is a form of dysautonomia, which means dysregulation of the autonomic nervous system. The autonomic nervous system regulates the bodily processes that happen automatically, without any thought on our part (like heart rate!). Normally, when we stand up, our body performs automatic responses to compensate for this positional change so that we remain conscious. In someone with POTS, this response doesn’t quite work as it should. And guess what happens then? Their heart races when standing up.

While there are several different subtypes of POTS (I’ll get to that in a second!), the orthostatic intolerance that occurs in POTS is because of inadequate circulation. Poor tightening of blood vessels (vasoconstriction) in the lower body when upright leads to heightened and rapid blood pooling in the pelvis and legs.

And guess where blood needs to be to maintain consciousness? Your brain! When you have POTS and you ask yourself why your heart races when standing up it’s because your brain is shouting at your heart to pump more blood, faster. This rapid increase in standing heart rate is your body trying desperately to pump more blood up to your brain because too much of it is pooling in your lower body. 

Make sense so far?

3 POTS Subtypes

According to a 2020 medical review, there are three subtypes of POTS, including neuropathic POTS, hyperadrenergic POTS, and hypovolemic POTS.

Neuropathic POTS

Neuropathic POTS — caused by a partial autonomic neuropathy — leads to decreased venous return and reduced stroke volume. This means that less blood is circulated above chest height while upright, causing reduced blood flow to the brain. As we learned above, a lack of blood flow to the brain is what triggers a fast standing heart rate and other POTS symptoms.

Hyperadrenergic POTS

Hyperadrenergic POTS basically means that your body has an overactive sympathetic nervous system (the bodily system responsible for the “fight-or-flight” response). This increased sympathetic nervous system activity promotes tachycardia and negatively affects blood flow to the brain. Those with hyperadrenergic POTS experience heightened plasma norepinephrine levels when upright. Norepinephrine is a compound released by the adrenal glands during times of stress that increases heart rate and blood pressure. So, essentially, people with this subtype of POTS are too often in the “fight-or-flight” mode because they have poor norepinephrine metabolism.

Hypovolemic POTS

A large percentage of POTS patients experience persistent hypovolemia, or low blood volume, either from deconditioning or altered response to plasma angiotensin 2 (Ang-II). While in healthy individuals Ang-II causes vasoconstriction, high blood pressure, and fluid retention, in POTS patients it doesn’t quite have that effect. What’s even more fascinating is that POTS patients tend to have elevated levels of Ang-II! It’s quite the paradox, isn’t it? Regardless, this low blood volume causes decreased venous return and stroke volume, which — boom! — makes your heart race when standing.

POTS Symptoms: More Than A Racing Heart When Standing 

Now that you understand the mechanisms behind why POTS symptoms occur and what the syndrome is, let’s talk about the symptoms themselves.

POTS commonly overlaps with other chronic illnesses, such as Ehlers-Danlos Syndrome (EDS), autoimmune diseases such as Hashimoto’s Thyroiditis and Sjrogen’s Syndrome, and Gastroparesis, to name only a few. (See more here.)

That being said, people can experience a variety of symptoms depending on the presence of additional syndromes. This is also why each POTS case is unique to each individual and treatment must be tailored to reflect that. However, besides feeling a fast standing heart rate, people with POTS can experience the following symptoms:

• Tachycardia
• Dizziness, lightheadedness
• Presyncope
• Fainting
• Low blood pressure (not always, can be high)
• Extreme fatigue
• Heat intolerance
• Exercise intolerance
• Shortness of breath
• Heart palpitations
• Chronic pain (esp. “coathanger” pain or rib cage pain)
• Anxiety or nervous feeling 
• Diarrhea, constipation, or alternating between the two
• Cold hands and feet, discolored feet (mottled appearance from blood pooling)
• Headache
• Nausea
• Tremors with adrenaline surges
• Insomnia, frequently waking up at night with a racing heart, chest pain, or excessive sweating (from adrenaline surges)
  

How Is POTS Diagnosed?

Diagnosing POTS can be tricky for several reasons. The worst obstacle to getting a diagnosis is that some doctors have never even heard about the syndrome. Or worse, they may say they don’t believe in it as a medical condition or that they refuse to treat you for “just some dizziness” or “occasional tachycardia.” Oh yeah, I’ve been there. Anyone else?

That being said, if POTS is something you seriously think you have, I’d highly recommend starting with some research. Locate specialists near you who are familiar with the syndrome. You’ll want to look for either a neurologist or a cardiologist who has experience diagnosing and treating POTS. Don’t waste your time with doctors who aren’t knowledgeable about it. If you’ve read my story, you know how much I struggled to be believed before finally going to Cleveland Clinic to get treated. 

The gold standard for diagnosing POTS is a tilt table test (TTT). For this test, you will be strapped onto a bed or table that moves you from a horizontal to a vertical position. To be diagnosed with POTS, you must experience an increase of 30 bpm or more (40 bpm or more for those aged 12-19), or a pulse higher than 120 bpm, within the first 10 minutes of being upright. 

BUT — and this is a big but — this test doesn’t always result in a positive diagnosis for some people who actually do have POTS. Guess what? I happen to be one of those people. This is also where the diagnosing process can get tricky.

If you have POTS, you know that some days are better than others. That’s how it is with chronic illness — symptom severity ebbs and flows. I happened to be having a good symptom day when I had my TTT. Plus, it was scheduled for the afternoon, and morning is typically when my symptoms are the worst. While I still showed an increase in heart rate when tilted upright, it didn’t meet the 30 bpm increase criteria. (I just missed it!) But I still had all the symptoms!!!

So there are additional tests doctors can do that point to POTS. This includes a QSART, blood work for other POTS causes, an echocardiogram, an autonomic breathing test, and a hemodynamic tilt test, the latter being just the test that gave me a positive diagnosis. Specialists should be familiar with these additional testing methods. Bottom line, don’t give up if one test result comes back normal and you still have POTS symptoms.

How To Treat POTS

While there is no cure for POTS, there are ways you can manage this chronic illness.

I’ve dedicated the last year and a half to learning as much as I can about this syndrome and to heal myself from its debilitating symptoms. There are days, even months when I feel successful at this, but there are days when I feel like I’ve taken a giant leap backward. That’s the nature of this chronic illness, and for those of us that don’t spontaneously go into remission, we have to learn how to master symptom management.

Lucky for you, I have many blog posts where I discuss lifestyle changes for POTS. My goal is to help you figure out how to best manage your unique case.

While everyone experiences POTS differently, there are four major lifestyle changes that help POTS patients the most. They include eating a high-salt diet, increasing fluid intake (water and electrolyte beverages), wearing compression, and sticking to an exercise program, such as the Levine Protocol.

When your heart races when standing it can be a terribly uncomfortable and sometimes distressing sensation! That being said, self-care is so important with POTS as well. Carve out some “me-time” now and again to check in with your mental and emotional wellness. Find a support group, talk with loved ones you trust, or make time for a relaxing hobby to distract yourself — whatever you need to take care of your mental health and help you through bad days!

There are also medications doctors prescribe to help treat POTS. Many common prescriptions are fludrocortisone, low-dose beta-blockers, midodrine, pyridostigmine/mestinon, ivabradine, and SSRI’s. I take pyridostigmine, and this works really well for me — but again, it may not be the best answer for everyone. Your doctor will work with you to determine which medications may be the right fit for you. 

I would also highly recommend purchasing a heart rate monitor for both exercise and everyday use. Fitbit watches are great for everyday use! I use the Fitbit Sense smartwatch to monitor my heart rate all through the day, during exercise, and even while I sleep so I can see any patterns or spikes in my heart rate. 

I can personally attest to how well the combination of lifestyle changes and medication works in managing POTS. In addition to medication, I’ve found that exercise has been the most helpful in treating my POTS. While it does suck to first get into an exercise program (you will likely feel worse at first, just a heads-up!), reconditioning your body to withstand being upright is key to treating POTS. Just take it slow and be kind to your body! (Check out more tips for exercising with POTS.)

If I notice my heart races when standing, it signals to me to drink more water or electrolyte drinks, eat more salt (I love pretzels!), recline my feet, and put on compression socks. It’s also good to have the documented heart rate data in a chart (FitBit does this, as do most heart rate monitor brands) that you can show your doctor. 

I also own a Polar H10 Heart Rate Sensor, which is the most accurate and precise way to measure heart rate in real-time. I wear this for upright exercise, like running, when I need to keep a very close eye on my heart rate. The only drawback with chest straps, in my opinion, is that they aren’t comfortable for all-day use — that’s where my Fitbit Sense comes to the rescue! 

Quick Summary

POTS is a type of dysautonomia that affects circulation. Symptoms present rapidly upon standing and resolve upon sitting or reclining. Common symptoms include rapid heart rate when standing up, dizziness, fainting or presyncope, severe fatigue, nausea, and exercise intolerance. Since it is such an underdiagnosed syndrome, patients who feel that their heart races when standing should seek out a neurologist or cardiologist who treats other POTS patients. They will perform diagnostic testing and organize a treatment plan for your unique case. While there is no cure for POTS, a combination of medication and lifestyle changes can help you manage this syndrome and get back to living a whole and fulfilling life!
 

Like this content? Be sure to share it to help spread awareness for POTS! If you have any questions about my experience with POTS, ask below! I’d love to hear from you!

XO,

Laurie