A
hiccup ( , ; also spelled
hiccough) is an involuntary contraction (
myoclonic jerk) of the
diaphragm that may repeat several times per minute. In
medicine, it is known as
synchronous diaphragmatic flutter (SDF), or
singultus, Latin for the act of catching one's breath while sobbing. The hiccup is an
involuntary action involving a
reflex arc. Once triggered, the reflex causes a strong contraction of the diaphragm followed about 0.25 seconds later by closure of the vocal cords, which results in the classic "hic" sound.