A hiccup is an involuntary contraction of the diaphragm that may repeat several times per minute. In medicine, it is known as synchronous diaphragmatic flutter , 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 second later by closure of the vocal cords, which results in the classic "hic" sound.
