THIS IS NOT MEDICAL ADVICE. IF YOU BELIEVE YOU HAVE VCD, PLEASE CONSULT A MEDICAL PROFESSIONAL.
Vocal cord dysfunction occurs when the voice box doesn't open properly. This can seem similar to asthma because of symptoms, but the difference with VCD is that it is the muscles that tighten causing trouble when breathing out (exhaling). People with asthma can have VCD.
(Image from Colorado allergy and asthma centres.)
Triggers:
Breathing in irritants - dust, chemicals or smoke.
Exercise
Cold/flu
Infection
GERD
Stress
Some medications
Symptoms:
Difficulty breathing (I sounded like a broken robot wheezing.)
Feeling of choking or suffocation
High pitched wheezing
Coughing
Tightness in throat or chest
Voice change
Hoarseness
Runny nose
My incident occured due to dust that I was standing pretty far away from. It started as a runny nose, then slight coughing followed by wheezing that was getting worse. After checking my pulse ox and peak flow (I have E-asthma and not so great lungs), I realised it wasn't my lungs, but still didn't know what it was so I recorded it and sent it to my respiratory doctor. I also showed it to some other doctors who all concluded it was VCD due to my HEDS, MCAS, and E-asthma (funky collagen, tissues, muscles + allergies.) The incident did settle itself after a hot drink, and luckily didn't progress to a full closure, which would've included fainting and not breathing for a few seconds.
VCD can occur in those with HEDS due to the vocal cord muscles being weak or having poor control. There isn't much knowledge around this yet as there aren't as many reported cases linking the 2, therefore there isn't treatment for it as such, other than regularly sipping water, avoiding triggers, and doing some breathing exercises.