Although inflation is not necessarily a bad thing for a growing economy, there have been numerous historical examples when inflation runs wild--a situation called hyperinflation. Some of the worst examples of hyperinflation have seen prices double in a matter of hours, with monthly inflation rates exceeding hundreds of trillions of percent. However, monthly inflation reaching 50% is generally considered to be the threshold for hyperinflation. What is hyperinflation, how does it occur and what happens to the value of money? Salman Khan of the Khan Academy explains.