Inducible laryngeal obstruction

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What is inducible laryngeal obstruction (ILO)?

Inducible laryngeal obstruction is a throat disorder that affects breathing. It is sometimes called vocal cord dysfunction, or paradoxical vocal cord movement. 

ILO happens when the vocal cords close when they should be open for breathing, creating a narrowing (obstruction) in the upper airway, at the level of the throat. ILO breathing is often noisy, and often misdiagnosed as asthma.

The video below shows what the voice box looks like during an ILO episode. The two white lines sitting in a V shape are the vocal cords. The space between them is the entrance to the airway (trachea).

Symptoms of ILO

Symptoms of ILO can vary from person to person. Individuals may experience a single or a number of symptoms, and the severity may vary.

ILO vs asthma

ILO is often confused with asthma, however, there are some key differences. It is important that ILO is diagnosed by a professional before any changes to medication are made. Frequently, both conditions can exist side by side.

ILO control

1. Identify what triggers ILO: Many things can trigger ILO. Your body may react differently to triggers depending on the environment, or situation you are in. Identifying what your triggers are can be useful for controlling ILO symptoms. Common triggers for ILO include:

2. Identify early warning signs that your ILO is about to start.  It is helpful to look out for signs of ILO. For most people, these signs include a tickle, irritation or tightness in the throat. These signs can act as a prompt to start your emergency breathing exercises, and could help to prevent or shorten an ILO episode.  

3. Make sure your throat is as healthy as possible:  It can be more difficult to control ILO if the lining of your upper airway (including mouth and throat) is dry. There are a number of things that can be done to improve throat care.

4. Reduce muscle tension in your throat, jaw, tongue and neck: It can be more difficult to control ILO if the muscles in our throat and neck are tight. Muscle tension restricts the movement of muscles, making it more difficult to open up the airway and improve breathing. Your SLT will be able to offer advice on the best exercises to release throat tension and tongue/jaw tension. Improving whole body breathing patterns can also help to reduce tension in the upper body.

5. Learn emergency breathing strategies: Some people try to avoid ILO triggers, but this is not always possible, especially outside of your own home. We recommend developing techniques to control your breathing if you do come into contact with triggers. These exercises can help to prevent an ILO episode from happening, or make an ILO episode shorter and/or less severe. You will work with your SLT to find emergency breathing techniques that prevent your vocal cords from squeezing together, making it easier to breathe. The most commonly used technique is ‘sniff puff puff’.

Examples of how to manage different triggers

If external irritants are a trigger, it can be helpful to start your breathing exercises BEFORE you come into contact with the trigger. For example, if you are about to walk outside into cold air, you could start your breathing exercises before you get outside. In some cases this isn’t possible (or you might forget) and your ILO symptoms could start without warning. In these cases, start your breathing exercises as soon as possible to ‘get you out of the ILO episode’. This aims to make the ILO episode shorter and less severe.

If internal irritants are a trigger, e.g., mucus in the throat, you could focus on improving your hydration and throat care to make the mucus thinner and less irritating.  You could also work on changing how your throat muscles respond to the sensation of an irritation e.g., by swallowing mucus and taking gentle breaths in and out through the nose, rather than throat clearing or breath holding.  

If voice use is a trigger, you can work on breathing patterns, voice exercises and/or personalised throat relaxation exercises. These help to improve how well the muscles around your lungs coordinate with the muscles in your voice box.

If exercise is a trigger, you can work on introducing helpful breathing patterns, and personalised breathing exercises. It can be beneficial to introduce these before you reach the most challenging point of exercise. You can also work on pacing your exercise.

If emotions are a trigger, your SLT would work with you to explore any unhelpful thinking patterns that may be driving throat tension. You would work together to find different ways to support your wellbeing, and identify the most helpful breathing exercises. Emotions could be specifically related to ILO e.g. the fear of being unable to breathe or beliefs about what other people think about your ILO. It is however possible for emotions about ‘non-ILO related factors’ to affect throat muscles and make them more likely to tighten up.

How is ILO diagnosed?

First, your respiratory doctor will look for other causes of your breathlessness. Then a speech and language therapist will observe your breathing patterns and assess your voice box when ILO symptoms are occurring. This is done by conducting a nasendoscopy.

Top tips for throat care

1. Reduce irritation

Ensure you are well hydrated:

Drink 1.5 to 2 litres of water each day, unless advised otherwise by your Doctor.

Carry a water bottle at all times for regular sips of wate.

Avoid caffeinated/ alcoholic drinks.

Manage any sinus problems, eg, by using a saline sinus rinse

Manage any acid reflux or heartburn

2. Steam Inhalation (aim for 8-10 times per day):

Inhale the steam from a cup of your favourite caffeine free hot drink/ cup of boiling water.

Breath shower steam when having a shower.

Run hot water into a sink or basin and inhale the steam.

Run a washcloth under hot water, wring it out, and hold it near your mouth and nose and breathe in.

Try using a steam inhaler cup.

3. Medication

Some medications have a drying effect on the throat, use steam to combat this.

Rinse your mouth out and steam before and after using powdered inhalers.

Use a spacer with your inhalers if you can.

Ask your medical team if there are any alternative medications, that are less drying in the throat.