Hiccups are spasms of the diaphragm muscle. They are repeated and cannot be controlled. This results in an odd, sometimes uneasy gasping sensation and sound with each hiccup.

Hiccups are caused by any number of factors that irritate the diaphragm. The diaphragm is a sheet of muscle that separates the abdominal cavity from the chest cavity. Its main function is to help the lungs draw in air during breathing.

Phrenic Nerve and Diaphragm
Phrenic Nerve
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