Hiccups are simple enough to explain.
According to a doctor who studies hiccups, there is a hiccup center in the brain that triggers a spasm of the esophagus setting in motion the cycle leading to hiccups. This, he thinks, is a protective mechanism to keep a person from choking on food or drink. Luckily, hiccups are generally harmless and don't last very long. If this doesn't stop the hiccups right away, repeat it three times at two-minute intervals. With your neck bent backward, hold your breath for a count of 10.