Nathan Kessel discovers that his girlfriend says his snoring sounds like an elephant while a kitten sleeps through it all.

We’ve all been there: You’re snug in bed, moments away from drifting off, only to be jolted back into a state of annoyed wakefulness by a loud, persistent sound coming from the other side of the bed.

That rattling sound coming from your bedroom might be more than just an annoyance. Acute snoring—the loud, chronic kind that keeps partners awake and sometimes even wakes the snorer—often signals ...