Why do people hiccup?

Spasm: A hiccup is a sudden involuntary contraction of the diaphragm. They can happen if the phrenic nerve (the one that innervates the diaphragm) is irritated, but most often we have no idea why hiccups occur.

Possible causes:: Some possible causes of hiccups can include: drinking too much alcohol or carbonated beverages, eating too fast & swallowing air; anxiety/ stress; injury to the vagus or phrenic nerves, noxious odors & benzodiazepine use. Hiccups can also occur as the result of chronic medical conditions or strokes.