And to add to this, if your bump has an ngon pole on it, use zbrushes alternative smoothing algorithm designed for poles. To activiate it, hold shift and begin to smooth, then let go of shift while you are smoothing. This makes the pole smooth. Good luck with your pole bump.
If you're using Zbrush, start by going to a lower subdivision of your head and simply hold down Shift while smoothing out your bump with a few careful strokes of the pen, provided you got a wacom tablet. Be careful though, you dont want to make a dent in your head either. Hope this helps.