What nerves are involved with hipcups?

The phrenic nerve and vagus nerve are the two main nerves involved in hiccups. The phrenic nerve controls the diaphragm, the muscle that separates the chest cavity from the abdominal cavity. The vagus nerve controls the muscles of the throat, esophagus, and stomach. When these nerves are irritated or stimulated, it can cause the diaphragm to contract and the vocal cords to close, which produces the characteristic hiccup sound. Hiccups can also be caused by other factors, such as eating too quickly, drinking alcohol, or smoking.