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Exercise-Induced Laryngeal Obstruction (EILO)

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This information was reviewed and approved by J. Tod Olin, MD, MSCS (8/31/2017).

Exercise-induced laryngeal obstruction (EILO), is also called vocal cord dysfunction (VCD). It causes shortness of breath during exercise, which can be very severe.

EILO is a serious condition that can cause profound changes in a person’s quality of life. Having  shortness of breath during exercise can be extremely distressing. This condition prevents children from playing comfortably. It affects the performance of even the most elite athletes. EILO is frequently misdiagnosed as asthma. Asthma medications do not help this condition.

National Jewish Health is one of only a few centers in the world that can perform today’s most advanced diagnostic test for EILO. It is called the continuous laryngoscopy during exercise. This test combines all of the features of a cardiopulmonary exercise test with real-time video of the vocal cords.

National Jewish Health is the only center in the world to offer a new treatment of EILO. It is called therapeutic laryngoscopy during exercise. This procedure was invented by our team.

National Jewish Health experts also invented novella new series of breathing techniques for this condition.


Normal and Abnormal Vocal Cord Function

To understand EILO, it is helpful to understand how the vocal cords normally function. The vocal cords are located at the top of the windpipe (trachea). They vibrate to produce noise and voice. Breathing causes the vocal cords to open. This allows air to flow through the windpipe (trachea) and into the lungs. During episodes of EILO, the vocal cords c partly or nearly completely tighten. This leaves a restricted opening for air to flow through the windpipe. The small open for air causes shortness of breath.


History of EILO

Exercise-induced laryngeal obstruction (EILO)/vocal cord dysfunction (VCD) was discovered relatively recently. Some descriptions of possible cases first appeared in medical literature in 1842 and then again in 1951. Both times the cases were inaccurately characterized as having factitious self-created symptoms.

In 1983, a group of people with "uncontrolled asthma" were evaluated at National Jewish Health. A team of pulmonologists, otolaryngologists, psychiatrists and speech-language pathologists accurately identified the condition. They provided treatment for what we now know as VCD. Their findings were published in the New England Journal of Medicine in 1983.

People with symptoms limited to exercise were described in the years that followed. Since the 1980s, we have come to realize that they do not share all of the features seen in the first group described in 1983.


Our Specialists

  • Elizabeth M. Fan

    Elizabeth M. Fan, PA-C

  • Marjorie Patricia George

    Marjorie Patricia George, MD

  • Darlene Kim

    Darlene Kim, MD, FACC

  • Michael P. Mohning

    Michael P. Mohning, MD

  • J. Tod Olin

    J. Tod Olin, MD, MSCS

  • Zulma X. Yunt

    Zulma X. Yunt, MD