With traditional photography there were a number of ways to 'Push-Process' film to get effectively higher sensitivities, like extending development time or increasing the temperature of the developer. The price for doing this was an increase in grain and loss of dynamic range.

Images here illustrate results from various techniques to 'push-process' low ISO digital images to usable equivalent higher ISOs, although the same price has to be paid as with film since it increases image noise and lowers dynamic range.

Sometimes though, as with film, it is worth the price.