Why POTS Can Feel Like Anxiety

The short version

POTS and anxiety share many of the same body sensations because both involve the same stress-response system. The racing heart, shakiness, chest tightness, air hunger, and sense of dread that many people with POTS feel when upright are real physical signals. They come from the body working hard to keep blood flowing to the brain.

Research shows that the fast heart rate in POTS is driven by being upright, not by worry or fear [3, 4]. Anxiety can still be present alongside POTS, and when it is, it deserves care too. Both things can be true at once, and understanding the mechanism helps you and your care team treat each one well.

What happens when you stand up

Every time anyone stands, gravity pulls blood down toward the legs and belly. The nervous system responds within seconds: blood vessels tighten and the heart speeds up a little to push blood back up to the heart and brain.

In POTS, this adjustment does not work as smoothly. Depending on the person, blood vessels may not tighten enough, blood volume may be low, or the stress-response system may overreact [1, 2]. The body makes up for it the only way it reliably can: by turning the heart rate up much more than usual. In adults, POTS is defined by a heart rate rise of at least 30 beats per minute within 10 minutes of standing (at least 40 in ages 12 to 19), without a large drop in blood pressure [1, 2].

That fast heart rate is the body doing its job under strain. It is a compensation, not a malfunction of willpower or mood [3, 4].

The alarm system turns up

The system that speeds your heart when upright is the sympathetic nervous system, the same “fight or flight” system that drives anxiety. Its main chemical messenger is norepinephrine (noradrenaline), a close relative of adrenaline.

When this system ramps up to keep blood flowing, it produces the same sensations whether the trigger is a scary thought or gravity:

• Pounding or racing heart
• Shakiness or trembling
• Sweating, nausea, or a fluttery stomach
• Feeling keyed up, restless, or on edge
• A sense of dread or that something is wrong

Some people have a pattern called hyperadrenergic POTS, where standing norepinephrine levels climb to 600 pg/mL or higher [2, 5]. Tremor, sweating, nausea, and a wired feeling are especially common in this group [2]. The body is producing stress chemistry in response to posture. The brain then feels that chemistry, and it feels like fear.

Less blood reaching the brain

In a large subset of people with POTS, blood flow to the brain drops more than normal in the first moments of standing [6]. Researchers have shown that this dip can come before, and appears to trigger, faster and deeper breathing [6, 7].

That overbreathing lowers carbon dioxide in the blood. Low carbon dioxide narrows the blood vessels in the brain, which reduces brain blood flow further and also speeds the heart [7]. About half of people with POTS show this low carbon dioxide pattern when upright [8].

The result is a loop that feels exactly like a panic attack:

• Air hunger, or feeling you cannot get a full breath
• Lightheadedness or a floaty, unreal feeling
• Tingling in the hands, feet, or face
• Chest tightness
• Trouble thinking clearly (brain fog)

In one study, giving people with this pattern extra carbon dioxide to breathe brought their heart rate and blood pressure back toward normal [7]. That points to a physical cause, not a psychological one.

How the brain reads body signals

Your brain is constantly reading signals from your heart, lungs, and gut. This sense is called interoception. The brain uses those signals to guess what is happening and how you should feel.

When the heart suddenly races for no obvious reason, the brain looks for an explanation. Throughout human history, a pounding heart has usually meant danger. So the brain may label the sensation as fear, even when the real cause is posture [9].

Research in POTS supports this. One study found that people with POTS reported more anxiety about body sensations than healthy controls, but not more social anxiety or trauma-related symptoms [9]. The authors concluded the anxiety seemed to grow out of unpredictable body signals rather than an anxious personality [9]. Over time, it is understandable to become watchful of your body when it keeps surprising you. That watchfulness is a learned response, and it can be retrained.

What the research says about POTS and anxiety

The evidence is clear that POTS is not caused by anxiety, and also that anxiety can show up alongside it. Both points matter.

The fast heart rate is driven by posture, not fear. In a Mayo Clinic study, people with POTS had a large heart rate rise when blood was actually pulled toward their legs, but no rise during a sham version of the same test that felt identical. They also did not have exaggerated heart rate responses to a mental stress task [3, 4].

Anxiety questionnaires can overcount. Common anxiety scales ask about racing heart, dizziness, and shakiness. People with POTS score higher on these because of their physical symptoms. In one study, people with POTS scored as moderately anxious on such a scale, yet did not show excess cognitive anxiety, meaning worry and fearful thinking [10].

Some people with POTS do have more anxiety. Other research has found higher anxiety and greater fear of heart-related sensations in POTS [11]. Depression and anxiety symptoms are common in POTS, as in many chronic conditions [12]. Living with unpredictable symptoms, and often years of being dismissed, is stressful.

Bottom line: having POTS does not mean your symptoms are “just anxiety.” Having anxiety does not mean you do not have POTS. If both are present, both deserve treatment, and managing one can make the other easier to manage.

Clues that point toward POTS

No single clue proves which is which, and a clinician should make that call. These patterns can help you describe your symptoms clearly.

Pattern	More typical of POTS	More typical of anxiety alone
Link to posture	Starts or worsens with standing or sitting up; eases within minutes of lying down [1, 3]	Not tied to body position
Common triggers	Heat, hot showers, large meals, standing still, after illness, around menstrual periods [1, 2]	Worrying thoughts, feared situations
Heart rate	Rises by 30 or more beats per minute on standing and stays up while upright [1, 2]	Rises with fear or stress, in any position
Other signs	Purple or red blotchy legs when standing, fatigue, exercise intolerance [1, 2]	Fewer physical signs between episodes

Helpful to bring to your provider: a few days of notes on when symptoms happen, what position you were in, and any heart rate readings lying down and after standing. Ask your provider before doing a standing test at home if you tend to faint.

What helps

The most useful strategies work on the physiology, which also quiets the alarm signals the brain is reading.

• Support blood volume. Extra fluids and salt are first-line for many people with POTS [1, 2]. Check with your provider first, since this is not right for everyone.
• Use compression. Waist-high or abdominal compression reduces how much blood pools when upright [2].
• Change positions in stages. Sit at the edge of the bed before standing. Tense your leg and buttock muscles or cross your legs when standing still.
• Build tolerance gradually. Exercise that starts lying down or seated (rowing, recumbent bike, swimming) and slowly progresses to upright has improved symptoms and heart rate in research trials [13].
• Slow your breathing when upright. Because overbreathing drives some POTS symptoms [7, 8], low, slow breathing may help. This has not yet been tested directly in POTS trials.
• Name it accurately. Saying “this is my blood pressure system working hard” instead of “something is wrong” may ease the fear that unpredictable body signals can trigger [9].
• Treat anxiety if it is there. Therapy such as cognitive behavioral therapy can help with health worry and body-focused fear. Seeking this care does not mean your symptoms are imagined.

If you have chest pain, fainting with injury, or symptoms that feel different from your usual pattern, seek medical care.

References

1. Raj SR. Postural tachycardia syndrome (POTS). Circulation. 2013;127(23):2336-2342. Link
2. Vernino S, Bourne KM, Stiles LE, et al. Postural orthostatic tachycardia syndrome (POTS): state of the science and clinical care from a 2019 National Institutes of Health expert consensus meeting, Part 1. Auton Neurosci. 2021;235:102828. Link
3. Masuki S, Eisenach JH, Johnson CP, et al. Excessive heart rate response to orthostatic stress in postural tachycardia syndrome is not caused by anxiety. J Appl Physiol. 2007;102(3):896-903.
4. Joyner MJ, Masuki S. POTS versus deconditioning: the same or different? Clin Auton Res. 2008;18(6):300-307. Link
5. Sheldon RS, Grubb BP, Olshansky B, et al. 2015 Heart Rhythm Society expert consensus statement on the diagnosis and treatment of postural tachycardia syndrome, inappropriate sinus tachycardia, and vasovagal syncope. Heart Rhythm. 2015;12(6):e41-e63.
6. Del Pozzi AT, Schwartz CE, Tewari D, Medow MS, Stewart JM. Reduced cerebral blood flow with orthostasis precedes hypocapnic hyperpnea, sympathetic activation, and postural tachycardia syndrome. Hypertension. 2014;63(6):1302-1308. Link
7. Stewart JM, Pianosi P, Shaban MA, et al. Postural hyperventilation as a cause of postural tachycardia syndrome. J Am Heart Assoc. 2018;7:e008854. Link
8. Stewart JM, Medow MS, et al. Anticipatory central command on standing decreases cerebral blood velocity causing hypocapnia in hyperpneic postural tachycardia syndrome. J Appl Physiol. 2023. Link
9. Owens AP, Low DA, Iodice V, Critchley HD, Mathias CJ. The genesis and presentation of anxiety in disorders of autonomic overexcitation. Auton Neurosci. 2017. Link
10. Raj V, Haman KL, Raj SR, et al. Psychiatric profile and attention deficits in postural tachycardia syndrome. J Neurol Neurosurg Psychiatry. 2009;80(3):339-344. Link
11. Anderson JW, Lambert EA, Sari CI, et al. Cognitive function, health-related quality of life, and symptoms of depression and anxiety sensitivity are impaired in patients with the postural orthostatic tachycardia syndrome (POTS). Front Physiol. 2014;5:230. Link
12. Raj V, Opie M, Arnold AC. Cognitive and psychological issues in postural tachycardia syndrome. Auton Neurosci. 2018;215:46-55. Link
13. Fu Q, VanGundy TB, Galbreath MM, et al. Cardiac origins of the postural orthostatic tachycardia syndrome. J Am Coll Cardiol. 2010;55(25):2858-2868.