Vocal Cord Dysfunction (ILO): Symptoms, Diagnosis and Treatment

What happens during ILO?

The larynx, or voice box, sits at the top of the windpipe. During an ILO episode, the vocal folds or nearby structures narrow when they should remain open for breathing. This reduces airflow through the upper airway. “Vocal cord dysfunction” is a familiar older term; ILO also includes obstruction involving structures around the vocal folds. [1], [2]

Episodes may begin abruptly and settle between attacks. This can make symptoms difficult to demonstrate at a routine appointment. A normal examination when you feel well does not automatically explain away what happened. [1]

Symptoms and possible triggers

People may describe difficulty breathing in, throat tightness, a choking sensation, noisy breathing, cough or a change in voice. Throat irritation and repeated throat clearing may also occur. These features suggest questions for the clinician; none is a diagnosis by itself. [2], [3]

Possible triggers include vigorous exercise, perfume or cleaning sprays, smoke, cold air, talking and laughing. Reflux, nasal symptoms or a recent infection may contribute to irritation in some people. A symptom diary can help identify the circumstances that precede episodes. [2], [3]

Stress can be a trigger or a consequence of frightening breathing symptoms. ILO should not be dismissed as “just anxiety.” Assessment needs to consider both airway function and the impact symptoms have on daily life.

How is ILO different from asthma?

These patterns overlap. Poor response to an inhaler does not prove ILO, and suspected ILO is not a reason to stop prescribed asthma medication. If symptoms persist despite treatment, review the diagnosis, inhaler technique and possible coexisting conditions with your clinician. Read our asthma guide.

How is vocal cord dysfunction diagnosed?

Start with a detailed account of the episodes: what triggers them, how quickly they begin, whether the sound occurs while breathing in or out, and how long recovery takes. The doctor also considers structural throat problems and other causes of breathlessness. [1], [4]

Spirometry can help, but has limitations

A spirometry test may include a flow-volume loop that records breathing in and out. It can sometimes provide a clue, but results may be normal between episodes. Spirometry alone cannot reliably confirm or exclude ILO. [1]

Laryngoscopy during symptoms

A small flexible camera passed through the nose allows the clinical team to observe the larynx. When appropriate, symptoms are reproduced in a controlled setting so the team can see whether obstruction occurs. This is different from deliberately provoking symptoms at home. [4]

When exercise is the trigger

Exercise-induced laryngeal obstruction (EILO) may need continuous laryngoscopy during exercise: the larynx is observed while the patient exercises under supervision. A resting examination may miss the problem. Availability of this specialized test varies, and referral may be needed. [5]

At consultation, ask what the proposed test is meant to answer, where it is available and what to do with your usual medicines beforehand.

What treatment usually involves

After diagnosis, a speech and language therapist experienced in upper-airway disorders can teach ways to reduce throat tension and improve control of breathing. Treatment may include laryngeal-control exercises, cough-control strategies, voice work and recognition of early warning sensations. [3], [6]

Your clinician may also address contributing problems such as nasal irritation, reflux symptoms or asthma. Our guides to post-nasal drip and nasal allergy explain some related symptoms. [3]

Practice the techniques taught for your own breathing pattern and triggers. Generic instructions online are not a substitute for an individualized plan, especially when asthma or another condition may also be present. Follow-up can focus on fewer episodes, easier recovery and return to activity. [2]

A respiratory consultation can help organize the assessment and appropriate ENT or speech-therapy referral. It should not be assumed that every clinic provides specialist laryngoscopy or EILO testing.

When symptoms need urgent assessment

If you already have confirmed ILO, use the personalized plan your team has taught you. Seek help when an episode is unusually severe, different from your usual pattern or fails to settle as expected. Tell the treating team about any coexisting asthma and your prescribed action plan.

Preparing for your consultation

• Write down the timing, duration and suspected triggers of episodes.
• Bring previous spirometry, ENT reports and a list of inhalers and other medicines.
• Describe changes in voice, swallowing, exercise tolerance and nasal or reflux symptoms.
• Explain what treatment has helped, what has not and how symptoms affect work or exercise.

This information helps the clinician choose an investigation that matches the question instead of repeating tests without a clear purpose.

Patient videos in English and Urdu

The original article’s videos remain available: vocal cord dysfunction explained in English and Urdu patient information. Use them alongside an individual assessment and treatment plan.