A paraphilia is an uncommon, intense, and persistent sexual arousal or attraction to anything not sexual by nature. It has also been defined as a sexual interest in anything other than a legally consenting human partner. Paraphilias are contrasted with normophilic ("normal") sexual interests, although the definition of what makes a sexual interest normal or atypical remains controversial.
The exact number and taxonomy of paraphilia is under debate; Anil Aggrawal has listed as many as 549 types of paraphilias. Several sub-classifications of paraphilia have been proposed; some argue that a fully dimensional, spectrum, or complaint-oriented approach would better reflect the evident diversity of human sexuality. Although paraphilias were believed in the 20th century to be rare among the general population, subsequent research has indicated that some level of paraphilic interests are relatively common.