A hiccup is a manner of forced intake of breath, caused by muscle spasms in the chest and throat in short involuntary moment of the diaphragm. There are many causes for hiccups, but the most common is exasperation of the stomach or the oesophagus. The “hic” noise arises when the breath is cut off by the shatter lock of your glottis. Other things that cause hiccups comprise skull fracture, epilepsy, tuberculosis and believe it or not, constipation says some doctors. Hiccups might not have peculiar reasons always but most of the times it turns upon having heavy food or non stop eating. Not all cases are normal hiccups, but sometimes it becomes persistent.
Evolutionary studies have proposed that it is a remnant of earlier amphibian respiration. Hiccups may be elicited by a number of common human circumstances. Rarely, they can be a sign of severe medical troubles. Infections, CNS disorders, Nerve damage/irritation, etc., might be some of the medical causes.