Hiccups are involuntary contractions of the diaphragm — the muscle that separates your chest from your abdomen and plays an important role in breathing. Each contraction is followed by a sudden closure of your vocal cords, which produces the characteristic "hic" sound.
Hiccups may result from a large meal, alcoholic beverages or sudden excitement. In some cases, hiccups may be a sign of an underlying medical condition. For most people, a bout of hiccups usually lasts only a few minutes. Rarely, hiccups may persist for months. This can result in malnutrition and exhaustion.