People get hiccups when the diaphragm involuntarily contracts due to a spasm, reports WebMD. When the spasm occurs, it causes the person to take a breath; however, the breath is stopped by the quick shutting of the vocal cords. This action causes the sound commonly known as a hiccup.
Normally hiccups last from a few minutes to a few hours, notes WebMD. When they do not go away after 48 hours, they are referred to as persistent hiccups. If the case of hiccups last for more than a month, they are called intractable hiccups. Persistent and intractable hiccups are uncommon and usually are caused by a more serious injury. Standard hiccups result from excitement, large meals or alcoholic beverages, says Mayo Clinic.