Air Hunger in POTS: Why You Can't Get a Full Breath

What Does Air Hunger Feel Like in POTS?

Breathlessness, called dyspnea, is a symptom with many possible sources. An American Thoracic Society statement calls it "a common, distressing symptom of cardiopulmonary and neuromuscular diseases" (Parshall, 2012). The statement describes several distinct breathing sensations. The POTS studies below measured breathlessness or dysfunctional breathing, not air hunger as a separate sensation. A review of orthostatic intolerance in people with headache lists "dyspnea or air hunger" among that condition's main symptoms, next to light-headedness, palpitations and fatigue (Mack, 2010).

Few studies use the term air hunger for POTS. A PubMed search of titles and abstracts for air hunger together with POTS, postural orthostatic, dysautonomia or orthostatic returned 1 result, the symptom list above. Breathlessness in POTS is studied under other names. Searching dyspnea, dyspnoea or shortness of breath together with POTS returned 55 results, and hyperventilation, hyperpnea or hypocapnia together with POTS returned 39, including the studies on this page (PubMed searches, 2026).

The clinic's position, laid out in our articles on low CO2, is that the low-CO2 version of air hunger comes on when you're upright and eases when you lie down.

Why Does POTS Cause Shortness of Breath When You Stand?

In our team's view, the fast heart rate in POTS is a rescue for brain blood flow. POTS is that compensation succeeding, and orthostatic hypotension is it failing. A tilt-table study of breathless POTS patients shows where breathing falls in that sequence.

The study compared 11 patients with suspected POTS whose chief complaint was breathlessness when upright with 10 healthy controls on a 70 degree head-up tilt (Del Pozzi, 2014). In the POTS group, brain blood flow velocity dropped during initial orthostasis. The drop came 17 ± 6 seconds before the volume of air breathed per minute began to rise and end-tidal CO2 (the CO2 measured at the end of each breath out) began to fall. Healthy controls also had a drop, a smaller one. The authors suggest the early drop in brain blood flow is what sets off the faster breathing. The study shows the order of events in 11 people, and the cause is the authors' hypothesis. The 3 POTS studies cited here come from one research group. A 2024 study from a different group also linked postural hyperventilation to reduced stroke volume and brain perfusion, and found chemoreceptor overactivity wasn't the main driver (Baker, 2024).

Lying Standing

Replay

How common low CO2 is in POTS depends on who is studied. One research group opens a 2023 paper by stating that 50% of people with POTS are hypocapnic (have low CO2) during standing, related to initial orthostatic hypotension, an early drop in blood pressure on standing (Stewart, 2023). That figure is the group's framing of its own patients. In an earlier study of 20 POTS patients aged 14 to 23, 10 hyperventilated and became hypocapnic on tilt and 10 didn't (Stewart, 2006), and another paper from the same group puts upright hyperventilation at about 25% of its POTS patients (Stewart, 2018).

For how low CO2 narrows the brain's blood vessels, see our article on hypocapnic cerebral hypoperfusion. For the full numbers from the 2023 study and what low CO2 feels like, see carbon dioxide and brain blood flow.

Is It Anxiety, Overbreathing or Asthma?

Low CO2 on standing is a measured finding in some people with POTS (Del Pozzi, 2014; Stewart, 2006). Whether overbreathing creates the feeling has been questioned outside POTS. A 1997 review argued that "recent investigations dismiss hyperventilation as an important symptom-producing mechanism" and reported that ambulatory CO2 monitoring showed "the vast majority of real-life attacks are not attended by decreases in pCO2" (Hornsveld, 1997). That review addressed hyperventilation syndrome in general, and it didn't study POTS.

Breathing-pattern problems and asthma can occur together. In 60 adults with difficult asthma and suspected breathing pattern disorder, 34 (57%) had hyperventilation symptoms on the Nijmegen questionnaire (Bondarenko, 2026). The authors concluded that evaluating both symptoms and physical findings is needed to recognize breathing pattern disorder in people with difficult asthma. We found no study that compares asthma with air hunger in POTS.

Our team's position, set out in our article on POTS and anxiety, is that anxiety can make POTS worse and breathing is one route.

Why Does Talking Leave You Out of Breath?

Our team's starting point is that breathing should run on its own: at rest, asleep and while running, you shouldn't have to think about it. Breathing is also unusual because you can take it over. You can't speed up your heart by thinking about it, but you can change your breathing by focusing on it.

In the clinic's view, speaking lays deliberate control on top of the automatic pattern. For some people the pace of speech is enough to leave them out of breath at the end of a sentence, or dizzy. When talking is the trigger, the team looks at how those deliberate commands dovetail with the automatic system. The team says this doesn't apply to everyone.

In the clinic's description, centers in the brainstem monitor signals about oxygen and CO2, the tension in the lungs and the pressure in the heart, then set the rhythm of breathing. If breathing gets too fast they slow it, and if it gets too deep they speed it up. That's the clinic's description of the control system, and no study on this page tests it in POTS.

Do Breathing Exercises Help Air Hunger?

The team says some people do really well with breathing exercises and some don't, so the team doesn't assume a drill will help. The research is thin, and most of it isn't about POTS.

How strong is the breathing-retraining evidence?

Study	Who	Design	What it found
Reilly, 2020	100 people with POTS referred for breathing treatment, 66 with before-and-after data	Retrospective cohort, physiotherapy with education and breathing control, no control group	Nijmegen score, breathing rate and breath-hold time improved after treatment
Bondarenko, 2025	2,119 adults with dysfunctional breathing across 68 studies	Systematic review	Most studies of breathing retraining reported positive effects, and the review rated the evidence low quality
Barker, 2013	Children with dysfunctional breathing	Cochrane review, searches to October 2013	No suitable trials were found
Norweg, 2025	42 adults with COPD, 20 in the breathing program	Randomized feasibility study	The program was feasible and acceptable. It wasn't a POTS study

The authors of the POTS series wrote that their results "provide a testable hypothesis that breathing retraining may provide breathless POTS patients with some symptomatic relief" (Reilly, 2020). In the 2025 review, breathing retraining showed positive effects in 29 of 34 studies on biochemical outcomes, and the review still concluded the evidence was low quality, with most studies at high or unclear risk of bias (Bondarenko, 2025). The Cochrane review concluded that "no suitable trials were identified for inclusion" (Barker, 2013). In the COPD study, the 4-week program of slow nasal breathing guided by a CO2 monitor had 84% session attendance and 5% dropout (Norweg, 2025).

Our team treats a deliberate deep breath as a way to override the pattern when needed. In a 2023 video the team noted that big, deep breaths blow off more CO2, so some people feel light-headed with deep breathing, and that typical breathing should be slow and not too deep.

When Should Shortness of Breath Get Checked?

Shortness of breath is also a symptom of heart and lung disease (Parshall, 2012), so have your doctor check it before you put it down to POTS. If it comes on suddenly, is severe, or comes with chest pain, fainting or blue lips, get emergency care.

Breathing pattern in POTS is a separate question. A 2023 study describes dysfunctional breathing in POTS as "complex, multifactorial, and not routinely assessed clinically outside of specialist centres," and says it has been identified mainly through cardiopulmonary exercise testing, hyperventilation provocation testing or specialist respiratory physiotherapy (Reilly, 2023).

How Does Our Team Work Out the Cause?

The clinic's goal is normal reflexive breathing, which the team calls the gold standard. When someone has to take control of breathing that should be automatic, the team asks 2 questions. Is the cause a neurological pattern, or is something in the metabolic system throwing off the CO2 ratio?

A timed breath-hold is one of the quick checks the clinic describes. You take a big breath, hold it and time how long you last, and the team asks whether a short hold points to breathing too much or too fast, called hyperventilation or tachypnea, or too deeply, called hyperpnea. The team says it's an indicator and not a definitive test for low CO2. In the office the team measures CO2 directly with a capnograph.

The team also asks why someone breathes through the mouth, because the reason differs from person to person. In the clinic's description, mouth breathing may feed on itself: it can inflame the nose, nasal breathing gets harder, and more breathing moves to the mouth. A deviated septum or a narrow palate that pushes breathing through the mouth can change how the body senses CO2 and oxygen, in the team's view. The team says it takes a big structural change before the pressure sensors in the neck are affected. We found no published study of mouth breathing, nasal breathing or a deviated septum in POTS: a PubMed search of titles and abstracts for postural orthostatic tachycardia together with mouth breathing, nasal breathing, deviated septum or nasal obstruction returned 0 results (PubMed searches, 2026).

In our team's view, medications that support blood volume or slow the heart can make standing easier, and they can't retrain a breathing pattern that's stopped running on its own.

Air Hunger in POTS: FAQ

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