Thank you for the link MsMcD.
I think that happens to me when I'm really upset - when I'm on the verge of bursting into tears but trying not to. It feels like my windpipe being strangled at the bottom of my neck (roughly in the thyroid area). I didn't know there was a name for it! It is really scary - it must be worse for you when they happen without any trigger. It's good to have a plan for times like that.