My ds is at this stage, tantrums followed by head banging. How long does this last, I don't fear he's doing it hard enough to seriously hurt himself but all that banging of his head can't be good? I had a cousin go through this stage and he ended up in a&e after smashing his head on a radiator. Was fine just big bruise, but I don't fancy ds doing the same. Is it just a case of waiting it out?