Jane Collier is an Occupational Therapist at Guys and St Thomas Hospital in London.  She wrote a leaflet on the pitfalls of chest breathing.  https://www.guysandstthomas.nhs.uk/resources/patient-information/therapies/abdominal-breathing.pdf

If you are doing costal breathing and experiencing anxiety, panic attacks then listening to this podcast will change your stuttering life.

If you are having relapses like an addict then you have to change you and not be addicted for a fix for fluency by attending a refresher. 

If you are holding your breath like a deep sea diver then you should also listen to change your stuttering life.