There is the mild tattoo or piercing end, like tramp stamps, and tribal armbands, to larger piercings, nipples and large tattoos, through to genital piercing, scarification, branding, needle play (play piercing), saline injecting and suspension.
There is however, a much more extreme version of body modification which has fascinated me for a long time. The fascination I feel is similar to that very human need to look at a car accident, a dead animal or vomit and shit when we should really look away. I am talking about self (or assisted) mutilation (such as genital bisection) and self (or assisted) amputation.
Why do people do it? There couldn't possibly be one single explanation, and not all of them are scarred by abuse and drugs.
I'm not here to analyse what they do, cos I ain't no doctor, but my strong stomach sometimes threatens to turn when I look..... but I still look.