Sometimes hiccups will occur because of a disturbance to the nerve pathways from the brain to the muscles involved. This explains why hiccups may occur with temperature changes or emotional situations. It is also the reason that a sudden shock can sometimes abolish an attack.
Persistent hiccups may signify problems in the brain, spinal cord or any of the structures around the diaphragm or chest wall.
Everyone has their own pet remedy for curing hiccups. Simply holding your breath is often effective. Breathing into a paper bag, the best remedy, increases the amount of carbon dioxide in the lungs, relaxing the diaphragm and halting the spasms.