BDSM is in fact a number of different related patterns for example B&D is bondage and discipline, D&S is domination and submission, and S&M is sadism and masochism. Whilst many of the practices involved in BDSM if performed on their own in nonsexual context can be considered to be unpleasant, or abusive, when performed with mutual consent they are considered to be enjoyable.
Pain, physical restraint, and servitude are all considered to be part of this behavior and they are commonly found in the femdom lifestyle where humiliation of the submissive is common practice and many men and women become sex slaves to their dominant partner. Whilst pain, physical restraint and servitude are all part of this it must be emphasized that these practices are only engaged in with mutual consent of the participants and they are practiced for mutual enjoyment. There is no abusive or undesirable actions carried out without consent.