<unk>  refers to sexual or non-sexual gratification in the infliction of pain or humiliation upon another person.<unk>  refers to sexual or non-sexual gratification from receiving the infliction of pain or humiliation.
Often interrelated, the practices are collectively known as sadomasochism as well as S&M or SM. These terms usually refer to consensual practices within the BDSM community.
Sadism and masochism
Malignant narcissism
Fetishism
Rational addiction
Voyeuristic disorder
Anhedonia pathophysiology
Psychopathy
Munchausen syndrome by proxy