EILO in Athletes — What It Is, Why It’s Misdiagnosed, and How to Treat It

Exercise-induced laryngeal obstruction (EILO) — also called vocal cord dysfunction (VCD) or paradoxical vocal fold motion (PVFM) — is one of the most commonly misdiagnosed breathing conditions in athletes. If you or your athlete has been struggling with breathlessness during exercise that doesn’t respond to inhalers, EILO may be the answer no one has given you yet.

What is EILO?

EILO is a condition in which the vocal folds or surrounding structures in the larynx narrow or close inappropriately during high-intensity exercise. Instead of opening fully to allow maximum airflow, the upper airway partially obstructs — making it feel difficult to breathe in.

Athletes typically describe it as their throat closing, a sensation of being unable to get air in, or a high-pitched noisy breathing sound (stridor) that others around them can hear. Symptoms come on suddenly at peak exercise intensity and typically resolve within minutes of stopping activity.

This rapid resolution is one of the most important clues that EILO, not asthma, may be the underlying issue.

Why is EILO so commonly misdiagnosed?

The symptoms of EILO overlap significantly with exercise-induced bronchoconstriction (EIB) — breathlessness, chest tightness, and noisy breathing during exercise. This overlap leads most athletes down the same path: a diagnosis of exercise-induced asthma and a prescription for an inhaler.

The problem is that EILO affects the upper airway — the larynx and vocal folds — not the lungs. Inhalers target the lower airways. They address the wrong structure entirely, which is why they provide no relief for EILO.

If you have been told you have exercise-induced asthma but your inhaler isn’t working, this is one of the strongest clinical signals that something else is going on.

Who gets EILO?

EILO affects an estimated 5–7% of adolescents and up to 34% of competitive athlete populations. It is more common in female athletes and is particularly prevalent among elite and high-achieving competitors — though it affects athletes of all ages, sports, and genders.

Common contributing factors include poor breathing mechanics, environmental triggers, medical comorbidities such as reflux, and psychophysiological factors like performance anxiety and nervous system dysregulation. In most cases EILO is multifactorial — meaning several of these contributors are present simultaneously, which is why a comprehensive treatment approach addresses more than just the mechanics.

How is EILO diagnosed?

Because EILO only appears at peak exercise, it cannot be diagnosed with standard breathing tests done at rest. This is why so many athletes go undiagnosed — their test results come back normal and their symptoms are attributed to anxiety, deconditioning, or undertreated asthma.

The gold standard diagnostic test is the continuous laryngoscopy exercise (CLE) test, in which a small flexible camera is passed through the nose while the patient exercises to peak intensity. This allows direct visualization of the vocal folds and laryngeal structures during the exact conditions that trigger symptoms.

How is EILO treated?

The good news is that EILO responds well to treatment — and that treatment does not require surgery or medication. Research shows that up to 89% of patients achieve significant improvement with specialist speech therapy.

At Functional Airway Lab, Dr. Karie Marsh — a licensed speech-language pathologist with a clinical doctorate and 15 years of clinical experience — provides individualized EILO rehabilitation combining two disciplines that evidence places at the center of effective care: speech-language pathology and functional breathing rehabilitation. The goal is not symptom management — it is resolution. Athletes leave with the skills to keep their airway open under real exercise load, in competition, and at peak intensity.

When should you seek help?

If you or your athlete experiences any of the following, it is worth having a conversation with a specialist:

Breathlessness that comes on suddenly at peak exercise intensity, difficulty breathing in rather than out, a high-pitched throat sound during exercise, symptoms that resolve quickly after stopping, or limited or no response to an inhaler.

You do not need a physician referral to contact Functional Airway Lab. We offer a complimentary 15-minute phone consultation to discuss symptoms, answer questions, and help determine whether an evaluation is the right next step.

In-person appointments are available at our Ventura, California office. Virtual telehealth sessions are available across California, Arizona, Colorado, Idaho, and Nevada.

---

Dr. Karie Marsh, SLPD, CCC-SLP is a licensed speech-language pathologist and EILO specialist at Functional Airway Lab in Ventura, CA. She holds a clinical doctorate in speech-language pathology from Rocky Mountain University of Health Professions, where her research focused on EILO in adolescent and young adult athletes.