The vagaries of this ailment: How MAC changes without fanfare

I "graduated" to nebbing 7% saline concentration in early January this year. My throat initially protested a bit, but quickly began to behave itself. I was pleased with the increase in mucous production that followed and things rocked along unremarkably until a few weeks ago when the mucous production skyrocketed, accompanied by retching coughing, sneezing and nose running like a garden spigot. Exaggerating a bit to make the point I began to think if the session didn't end soon I'd be utterly dehydrated. The throat mucous is exclusively clear, relatively viscid, and copious. It takes 10-15 minutes following the half-hour Thumper session for the coughing and water works to resolve.

Aside from my regret that my wife has to endure what must sound like I'm on the brink of extruding some vital organ from my throat and despite the inconvenience of the episodes, I actually am pleased to be bringing up so much mucous.

My puzzlement though, and the thought behind my "Title" above is how the big change just suddenly occurred without fanfare or any signal of an impending seachange. Don