While hiccups are usually harmless and don't last long in most people, some individuals can experience them chronically.

He tried the same with the hiccupping patient and it worked. He then published his paper in 1988 “Termination of intractable hiccups with digital rectal massage” for which he won an IgNobel prize.

If you hiccup for more than 48 hours or it recurs frequently, you may need to suspect intractable hiccups. In such cases, ...

There are three types of hiccups: acute, which last up to two days; persistent, which last up to a month; and intractable, which last even longer. The variety in causes means that for persistent ...