Masochism

In psychiatry, masochism is a personality trait where a person gets emotional satisfaction, pleasure and gratification from receiving pain or humiliation. It may or may not be sexual in nature.
Although the term has been used in psychiatry going back to the 19th century, it's meaning has been redefined as human behavior has become better understood. Like homosexuality, masochism is no longer considered a pathological behavior, but is accepted as a normal part of some people's sexual behavior in a consentual context. However, it's considered pathological when an individual consistently engages in behavior that is self-defeating.
Sadism and masochism as medical terms at Wikipedia
Category:Psychiatry