COVID-19 shortness of breath young woman
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Persistent shortness of breath in COVID-19 long haulers may be due to a treatable nerve injury. This is a reminder that shortness of breath is not always pulmonary. 

Sandy’s story

Sandy is a 42-year-old previously healthy woman who presented with a four-month history of an inability to have conversations or do Zoom meetings without feeling out of breath.

Her chest X-ray (CXR) and chest computerized tomography (CT) scan were normal. However, she had an unusual abnormality on her spirometry lung breathing test with flattening of the inspiratory curve.

She had clinical symptoms of mild COVID-19 disease in March 2020. However, she was not tested due to lack of access.

An ear, nose, and throat (ENT) examination of her larynx (voice box) in July 2020 showed abnormal closing of her vocal cords during quiet breathing. This is a time when they should have been open. This was identified as a paradoxical vocal fold movement disorder.

Treatment was instituted and included following a strict low-acid diet and doing speech therapy via telemedicine (due to the ongoing pandemic). Six weeks later, Sandy was able to carry on full conversations and run Zoom meetings without any shortness of breath. And, her examination was normal.

COVID-19 “long haulers” and shortness of breath

Persistent shortness of breath (SOB) long after recovery from presumed or documented COVID-19 infection is a vexing and troublesome symptom for untold thousands of people.  

SOB is a prominent symptom in people with what has come to be known as the COVID-19 “long hauler” syndrome.  In the United Kingdom, it is referred to simply as COVID “long”. What the “long” refers to is long after people ostensibly “recover” from COVID-19 there may exist a persistence of a variety of symptoms that seem to defy further diagnosis and treatment.

Two types of COVID-19 long haulers

According to Dr. Anthony Komaroff, MD, Editor in Chief of the Harvard Health Letter, there are two basic types of COVID-19 long haulers:

  • Those who experience some permanent damage to their lungs, heart, kidneys, or brain that may affect their ability to function.
  • Those who continue to experience debilitating symptoms despite no detectable damage to these organs.

Fauci weighs in on the cause of COVID-19 long haulers’ symptoms

There are several theories as to why there are persistent symptoms. One of the most popular theories comes from Dr. Anthony Fauci MD, Director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health.

Dr. Fauci feels that the COVID-19 patients in the “no detectable organ damage” group have a post-viral syndrome called myalgic encephalomyelitis. This was previously known as chronic fatigue syndrome. 

Once this diagnosis is made, and because COVID-19 is a new disease, very little hope is offered. We believe that we have identified a treatable diagnostic possibility that does in fact offer hope to these patients.

Persistent respiratory symptoms after other viral illnesses are common in COVID-19 long haulers

Those of us dealing with post-viral syndromes are quite familiar with upper respiratory-type symptoms following other viral-mediated illnesses, including

  • mononucleosis
  • severe acute respiratory syndrome. 

In the otolaryngology (ENT) world, we constantly treat viral illnesses from unknown sources that cause loss of smell, hearing, and voice—and also cause chronic cough and shortness of breath.  

This past June, New York City-based ENT and Allergy Associates, the largest single-specialty group of ear, nose, throat and allergy physicians in the United States, began to see patients with persistent SOB and/or cough.


They reported that they were quite ill around the time of the peak of the COVID-19 pandemic in New York City in March and April 2020.  In a recent study we published, along with Byron Thomashow MD, one of the foremost lung specialists, or pulmonologists, at the Columbia University Medical Center, we described a TREATABLE cause for the shortness of breath seen in these patients.

Related content: COVID-19: The Impact of the Early Failure to Respond

Common characteristics of our group of COVID-19 long haulers

The key to figuring out what may be the cause of the symptom was to make an accurate diagnosis. The group of patients we saw had the following common characteristics:

  1. Cough, fever, SOB between March and May 2020, not serious enough to warrant being hospitalized.
  2. The SOB persisted for 4-12 weeks at the time we first saw them.
  3. The SOB was generally not waking these patients up at night. It was also not affecting their exercise tolerance. In fact, they often reported feeling breathing difficulties after their activity. Talking, shouting, singing, karaoke, and odors typically brought on the SOB.  
  4. Due to limited access, only a handful of the group of patients we saw were able to get tested for COVID-19. Of the group that got tested, only a few developed antibodies to COVID-19. Further, only one of the few tested with the polymerase chain reaction test was positive.
  5. Imaging, including CXR and/or CT scan of the chest, were all unremarkable.
  6. A handful of patients were able to obtain a lung function test called spirometry. All of them showed a specific pattern on the flow-volume loop where there was flattening of the inspiratory curve. This means when the patient took a breath in, there was evidence of impaired airflow INTO the lungs. However, they had a normal expiratory curve, indicating normal airflow OUT of the lungs.

When your vocal cords close instead of open, you will be short of breath!

Normally when one is sitting, breathing quietly, one’s vocal cords, or vocal folds, are open, not shut. They close when you swallow, to protect the lungs. And they close and vibrate when you speak, to make sounds. Then, they open again.

The vocal folds can be comfortably examined with a tiny camera while the patient is awake in our exam rooms.

In all of these patients, their vocal folds were not moving in normal synch with their breathing—that is, they were closing more than 50% of their airway during quiet breathing. This is the opposite of what typically happens in a healthy individual.

The abnormal vocal fold closure could be brought out by having the patient say the five-word sentence “we see three green trees” and observing the vocal folds slowly closing afterward – for as long as nine seconds. During this time the patients feel as if they can’t catch their breath.

We concluded that the persistent vocal fold closure gave the patients their SOB. The flattening of the inspiratory curve on spirometry corroborated the laryngeal exam findings. 

This is different than laryngospasm where the vocal folds suddenly slam shut for prolonged periods of time. It also has a different symptom profile. 

What is vagal neuropathy?

The name for this abnormal vocal fold movement during breathing is vocal fold dysfunction. It is also called paradoxical vocal fold movement disorder.

It is often caused by inflammation of the vagus nerve.  The vagus nerve is one of the 12 cranial nerves that emanate from the brain. It governs breathing, talking, swallowing, among other vital functions.

If a viral illness causes inflammation of the vagus nerve, then breathing is typically going to be disturbed. This post-viral vagus nerve trauma is also called “vagal neuropathy”.

 One of the reasons it has traditionally been difficult to make the diagnosis of post-viral vagal neuropathy is that most people are unable to recall when or if they had a viral illness. This is especially true if the illness took place years ago.

In the current time of coronavirus, patients seem to be paying much more attention to when they began to feel ill.  

Speech therapy and a low acid diet can treat vagal neuropathy in COVID-19 long haulers

The good news here is that the cause of this abnormal breathing pattern can be treated with two non-invasive, non-pharmacologic means. We used a combination of approaches:

  • physical therapy
  • diet modification techniques.

The therapy is called respiratory retraining. This involves increased resistance breathing exercises that are generally administered by a speech-language pathologist. 

A low acid diet also works for these patients. There are a handful of very acidic foods and beverages that have a pH of less than 4. These include 

  • flavored sodas
  • bottled ice teas
  • citrus
  • tomato sauce (tomatoes are okay)
  • vinegar, including apple cider vinegar
  • wine, tend to aggravate the breathing issues.

We recommend that these foodstuffs be avoided.  

Using these two methods, all of our patients had resolution of their SOB.

There is hope for many COVID-19 long haulers who have shortness of breath

As we learn more about COVID-19 and long haulers we see many who have persistent SOB who have normal lung imaging. They are often told nothing further can be done for them. However, we have identified a possible, treatable cause for their symptoms.

In patients with persistent SOB, with or without cough, where the pulmonary imaging is unremarkable, one should obtain both a spirometry test and an ENT evaluation. This should happen whether or not they tested positive for, or have antibodies to, COVID-19; but certainly in those with positive testing.

This symptom may be due to a virus-related vagus nerve injury. The spirometry has a typical abnormal pattern and the neuropathy is readily identified with an office-based examination of the vocal folds.

Once diagnosed, the patient can receive the correct targeted treatment, and, just like our patient Sandy, they can return to enjoying their previously good quality of life.


  1. American Lung Association. What is Spirometry and Why is It Done?
  2. Carfi, A, Bernabei R, et al. Research Letter: Persistent Symptoms in Patients After Acute COVID-19; JAMA. 2020;324(6):603-605. doi:10.1001/jama.2020.12603 

  3. Komaroff A. The tragedy of the post-COVID “long haulers”; Harvard Health Letter, Oct. 15, 2020.

  4. Jonathan E A, Sujana C, Byron T. Covid-19 Era Post Viral Vagal Neuropathy Presenting as Persistent Shortness of Breath with Normal Pulmonary Imaging. Int J Pul & Res Sci. 2020; 4(4): 555641. DOI: 10.19080/IJOPRS.2020.04.555641

  5. Murry T, Branski R, et al. Laryngeal sensory deficits in patients with chronic cough and paradoxical vocal fold movement disorder. Laryngoscope; 2010 Aug;120(8):1576-81. doi: 10.1002/lary.20985.
  6. CDC Morbidity and Mortality Weekly Report. Symptom Duration and Risk Factors for Delayed Return to Usual Health Among Outpatients with COVID-19 in a Multistate Health Care Systems Network — United States, March–June 2020 Weekly / July 31, 2020 / 69(30);993-998

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