The prevalence of fetishism is not known with certainty. The majority of fetishists are male. In a 2011 study, 30% of men reported fetishistic fantasies, and 24.5% had engaged in fetishistic acts. Of those reporting fantasies, 45% said the fetish was intensely sexually arousing. In a 2014 study, 26.3% of women and 27.8% of men acknowledged any fantasies about "having sex with a fetish or non-sexual object". A content analysis of the sample's favorite fantasies found that 14% of the male fantasies involved fetishism (including feet, nonsexual objects, and specific clothing), and 4.7% focused on a specific body part other than feet. None of the women's favorite fantasies had fetishistic themes. Another study found that 28% of men and 11% of women reported fetishistic arousal (including feet, fabrics, and objects "like shoes, gloves, or plush toys"). 18% of men in a 1980 study reported fetishistic fantasies.

Fetishism to the extent that it becomes a disorder appears to be rare, with less than 1% of general psychiatric patients presenting fetishism as their primary problem. It is also uncommon in forensic populations.

Fetishism usually becomes evident during puberty, and may develop prior to that. No cause for fetishism has been conclusively established.

Some explanations invoke classical conditioning. In several experiments, men have been conditioned to show arousal to stimuli like boots, geometric shapes or penny jars by pairing these cues with conventional erotica. According to John Bancroft, conditioning alone cannot explain fetishism, because it does not result in fetishism for most people. He suggests that conditioning combines with some other factor, such as an abnormality in the sexual learning process.

Theories of sexual imprinting propose that humans learn to recognize sexually desirable features and activities during childhood. Fetishism could result when a child is imprinted with an overly narrow or "incorrect" concept of a sex object. Imprinting seems to occur during the child's earliest experiences with arousal and desire, and is based on "an egocentric evaluation of salient reward- or pleasure-related characteristics that differ from one individual to another."

Neurological differences may play a role in some cases. Vilayanur S. Ramachandran observed that the region processing sensory input from the feet lies immediately next to the region processing genital stimulation, and suggested an accidental link between these regions could explain the prevalence of foot fetishism. In one unusual case, an anterior temporal lobectomy relieved an epileptic man's fetish for safety pins.

Various explanations have been put forth for the rarity of female fetishists. Most fetishes are visual in nature, and males are thought to be more sexually sensitive to visual stimuli. Roy Baumeister suggests that male sexuality is unchangeable, except for a brief period in childhood during which fetishism could become established, while female sexuality is fluid throughout life.

Some types of BDSM play include, but are not limited to:

- Animal roleplay

- Bondage

- Breast torture

- Cock and ball torture (CBT)

- Erotic electrostimulation

- Edgeplay

- Flogging

- Golden showers (urinating)

- Human furniture

- Japanese bondage

- Medical play

- Paraphilic infantilism

- Predicament bondage

- Pussy torture

- Sexual roleplay

- Spanking

- Suspension

- Torture

- Tickle torture

- Wax play

Sadomasochism is the giving or receiving pleasure from acts involving the receipt or infliction of pain or humiliation. Practitioners of sadomasochism may seek sexual gratification from their acts. While the terms sadist and masochist refer respectively to one who enjoys giving or receiving pain, practitioners of sadomasochism may switch between activity and passivity.

The abbreviation S&M is often used for sadomasochism, although practitioners themselves normally remove the ampersand and use the acronym S-M or SM or S/M when written throughout the literature. Sadomasochism is not considered a clinical paraphilia unless such practices lead to clinically significant distress or impairment for a diagnosis. Similarly, sexual sadism within the context of mutual consent, generally known under the heading BDSM, is distinguished from non-consensual acts of sexual violence or aggression.

Sexual sadism disorder is the condition of experiencing sexual arousal in response to the extreme pain, suffering or humiliation of others. Several other terms have been used to describe the condition, and the condition may overlap with other conditions that involve inflicting pain. It is distinct from situations in which consenting individuals use mild or simulated pain or humiliation for sexual excitement. The words "sadism" and "" are derived from Marquis de Sade.

With paraphilic coercive disorder, the individual employs enough force to subdue a victim, but with sexual sadism disorder, the individual often continues to inflict harm regardless of the compliance of the victim, which sometimes escalates not only to the death of the victim, but also to the mutilation of the body. What is experienced by the sadist as sexual does not always appear obviously sexual to non-sadists: Sadistic rapes do not necessarily include penile penetration of the victim. In a survey of offenses, 77% of cases included sexual bondage, 73% included anal rape, 60% included blunt force trauma, 57% included vaginal rape, and 40% included penetration of the victim by a foreign object. Moreover, in 40% of cases, the offender kept a personal item of the victim as a souvenir.

On personality testing, sadistic rapists apprehended by law enforcement have shown elevated traits of impulsivity, hypersexuality, callousness, and psychopathy.

Although there appears to be a continuum of severity from mild ("hyperdominance" or "BDSM") to moderate ("paraphilic coercive disorder") to severe ('sexual sadism disorder), it is not clear if they are genuinely related or only appear related superficially.

Very little is known about how sexual sadism disorder develops. Most of the people diagnosed with sexual sadism disorder come to the attention of authorities by committing sexually motivated crimes. Surveys have also been conducted including people who are interested in only mild and consensual forms of sexual pain/humiliation (BDSM).

Most of the people with full-blown sexual sadism disorder are male, whereas the sex ratio of people interested in BDSM is closer to 2:1 male-to-female.

People with sexual sadism disorder" are at an elevated likelihood of having other paraphilic sexual interests.

BDSM is a variety of often erotic practices or roleplaying involving bondage, discipline, dominance and submission, sadomasochism, and other related interpersonal dynamics. Given the wide range of practices, some of which may be engaged in by people who do not consider themselves as practicing BDSM, inclusion in the BDSM community or subculture is usually dependent upon self-identification and shared experience.

The term "BDSM" is first recorded in a Usenet posting from 1991, and is interpreted as a combination of the abbreviations B/D (Bondage and Discipline), D/s (Dominance and submission), and S/M (Sadism and Masochism). BDSM is now used as a catch-all phrase covering a wide range of activities, forms of interpersonal relationships, and distinct subcultures. BDSM communities generally welcome anyone with a non-normative streak who identifies with the community; this may include cross-dressers, body modification enthusiasts, animal roleplayers, rubber fetishists, and others.

Activities and relationships within a BDSM context are often characterized by the participants taking on complementary, but unequal roles; thus, the idea of informed consent of both the partners is essential. The terms "submissive" and "dominant" are often used to distinguish these roles: the dominant partner ("dom") takes psychological control over the submissive ("sub"). The terms "top" and "bottom" are also used: the top is the instigator of an action while the bottom is the receiver of the action. The two sets of terms are subtly different: for example, someone may choose to act as bottom to another person, for example, by being whipped, purely recreationally, without any implication of being psychologically dominated by them, or a submissive may be ordered to massage their dominant partner. Despite the bottom performing the action and the top receiving they have not necessarily switched roles.

The abbreviations "sub" and "dom" are frequently used instead of "submissive" and "dominant". Sometimes the female-specific terms "mistress", "domme" or "dominatrix" are used to describe a dominant woman, instead of the gender-neutral term "dom". Individuals who can change between top/dominant and bottom/submissive roles—whether from relationship to relationship or within a given relationship—are known as "switches". The precise definition of roles and self-identification is a common subject of debate within the community.

Vorarephilia (often shortened to vore) is a paraphilia characterized by the erotic desire to be consumed by, or sometimes to personally consume, another person or creature, or an erotic attraction to the process of eating in general. Since vorarephilic fantasies cannot usually be acted out in reality, they are often expressed in stories or drawings shared on the Internet. The word "vorarephilia" is derived from the Latin "vorare" (to "swallow" or "devour"), and Ancient Greek φιλία ("philía", "love").

The fantasy usually involves the victim being swallowed whole, though occasionally the victims are chewed up, and digestion may or may not be included. Vore fantasies are separated from sexual cannibalism because the living victim is normally swallowed whole. Sometimes the consumers are human, but anthropormorphized animals, dragons, and enormous snakes also appear frequently in these fantasies. After consumption, the enlarged belly of the consumer is often described with great care. Vorarephiles sometimes prefer to differentiate between "soft vore" and "hard vore"; soft vore means the victim is swallowed whole and alive, and may possibly come back out in the case of a "non-fatal" scenario, while in hard vore the victim goes through a more gruesome, realistic digestion process, often getting chewed up beforehand.

Vore is most often enjoyed through pictures, stories, videos, and video games, and it can appear in mainstream media. In some cases, vorarephilia may be described as a variation of macrophilia and may combine with other paraphilias. Apart from macrophilia, vore fantasies often have themes of BDSM, microphilia, pregnancy fetishism, furry fetishism, "unbirthing" (a desire to be swallowed whole into the vagina and returned to the uterus), and sexual cannibalism.

One case study analysis connected the fantasy with sexual masochism, and suggested that it could be motivated by a desire to merge with a powerful other or permanently escape loneliness. With "no known treatment" for vorarephiles who feel ill at ease with their sexuality, psychologists at Toronto's Centre for Addiction and Mental Health have recommended trying to "adjust to, rather than change or suppress" the sexual interest. Medication for sex drive reduction could be used if deemed necessary.

Boot fetishism is a sexual fetish focused on boots. Boots have become the object of sexual attraction amounting to fetishism for some people and they have become a standard accessory in BDSM scenes (where leather, latex and PVC boots are favoured) and a fashion accessory in music videos. Boots are seen as perhaps the most fetishistic of all footwear and boots may be the most popular fetish clothing attire.

Uniform fetishism is a sexual fetishism where an individual is sexually aroused by uniforms.

Jennifer Eve Rehor of San Francisco State University points out that such data as exists on what she calls "unconventional" or "kink" sexual behavior is generally problematic because of the way that it has been collected, through criminal and clinical case studies. Behavior that appears neither in criminal trials nor in clinical studies (for example, because the individuals concerned do not commonly seek professional help) is therefore under-reported. Rehor therefore surveyed 1,764 female participants in "kink" behavior (mostly association with BDSM) in 2010-11, receiving 1,580 valid responses. What Rehor calls "urine play" is relatively infrequent, with only 36.52% of her sample reporting having done it or having had it done to them. In contrast, 93.99% of her sample reported having done spanking or having had it done to them, and 61.96% reported having used or been exposed to feathers/fur. It is impossible to extrapolate Rehor's data onto the general population, but her study does give a guide to prevalence in the North American BDSM community.

Wet and messy fetish (WAM), also known as sploshing, is a form of sexual fetishism whereby a person becomes aroused when copious amounts of a substance are applied to the naked skin, face, or to clothing. Several websites are dedicated to WAM.

Many people with WAM fetishes are drawn to the tactile sensations of wet or messy substances against their skin. Other individuals simply prefer the visual appeal of others getting wet or messy with products that have different textures, consistencies and colours. A subject will often be pelted with cream pies (sometimes using shaving foam rather than real cream pie filling), have slime dumped on them, or sit on cakes. Another common theme is the pouring of substances inside clothing while it is being worn; clothing chosen for this can vary from swimsuits or underwear to full outfits. Normal street clothes, either casual or office wear, are commonly featured in WAM productions, but many other types of outfits, from wedding attire to industrial overalls or more specialist fetishwear such as PVC, latex, or leather items may be used. White items are particularly popular with some fans of this fetish.

Messy substances most commonly focused on by WAM participants include whipped cream, raw eggs, milk, lotion (see lotion play), paint, oil, mud, pudding, chocolate sauce, fruit juice, beer, shaving foam, custard, baked beans, treacle, ketchup, ice cream, peanut butter, slime, and cake batter, among others.

A fetish for bodily fluids such as feces, urine, vomit, semen, and female ejaculate is not considered part of WAM. The former three are typically considered coprophilia, urophilia, and emetophilia; urophilia is somewhat commonly found in mainstream pornography. The latter two are also somewhat mainstream.

WAM fetish videos (made by both fans and commercial producers) may include nudity and sexual acts, while others may only feature fully clothed participants. Videos can be seen frequently public video hosting sites like YouTube. Some of these videos are flagged but most of them remain available despite the sexual undertones, mainly because a large majority of wet and messy videos posted publicly do not include nudity and are therefore considered suitable for all audiences to view. Indeed, not only is much WAM video content indistinguishable in any easily defined sense from the kind of slapstick featured in mainstream entertainment, but scenes of slimings or pieings from the mainstream media are often compiled and marketed by producers towards a WAM fetishist target audience.

Clothing fetishism or garment fetishism is a sexual fetish that revolves around a fixation upon a particular article or type of clothing, a collection of garments that appear as part of a fashion or uniform, or a person dressed in such a garment.

The clinical definition of a sexual fetish would require that a person be fixated on a specific garment to the extent that it exists as a recurrent (or exclusive) stimulus for sexual gratification.

One who exhibits a clothing fetish may be aroused by the sight of a person wearing a particular garment, or by wearing the garment oneself which can be because of the look one achieves by wearing it or the way it feels while it is being worn (and might also get some arousal by seeing somebody in it and imagining how it feels). In later case arousal may originate from the way its fabric feels (see clothing fetish by fabric type) or from the way the garment feels and functions as whole (restrictive clothing being an example).

Others with a clothing fetish may be aroused by the sight of such garments, even without wearing them and in the absence of other person wearing them, and may also derive pleasure from collecting them.

Among the most common uniforms in uniform fetish are those of a police officer, prison officer, soldier, schoolgirl, nurse, French maid, waitress, cheerleader, and Playboy Bunny. Some people also regard nuns' habits or even aprons as uniforms. The uniforms may be genuine, realistic, or they may be sexualized through the use of a very short miniskirt, a very long hobble skirt or a corset, through the use of stockings, fishnet tights, or high heels, or by being made of leather or latex, according to preference. Sometimes uniforms are used according to what activity is being done. For example, someone may wear a nurse's uniform to administer an enema or a police uniform to handcuff and cage someone. Two people may dress as inmates for cell mate-on-cell mate activities in a prison setting or as a submissive to a third (prison guard) roleplayer. This may add a sense of authenticity to the game play. A stripper dressed as a police officer is a popular fixture at birthday and bachelor parties. The "officer" begins with a mock "arrest", often using handcuffs, of the guest of honor before going into a dance routine.

Bondage pornography is the depiction of sexual bondage or other BDSM activities using photographs, stories, movies or drawings. Though often described as pornography, the genre involves the presentation of bondage fetishism or BDSM scenarios and does not necessarily involve the commonly understood pornographic styles. In fact, the genre is primarily interested with the presentation of a bondage scene and less with depictions of sexuality, such as nudity or sex scenes, which may be viewed as a distraction from the aesthetics and eroticism of the bondage scenario itself.

Historically, most subjects of bondage imagery have been women, and the genre has been criticized for promoting misogynistic attitudes and violence against women.

In order to determine the relative prevalence of different fetishes, researchers at the University of Bologna obtained a sample of at least 5000 individuals worldwide from 381 Internet discussion groups. The relative prevalences were estimated based on (a) the number of groups devoted to a particular fetish, (b) the number of individuals participating in the groups and (c) the number of messages exchanged. The top garment fetish was clothes worn on the legs or buttocks (such as stockings or skirts), followed by footwear, underwear, whole-body wear (such as costumes and coats), and upper-body wear (such as jackets or waistcoats).

There is some crossover between the wet and messy fetish and clothing destruction fetishes. Some WAM productions will see models start out fully dressed, usually in quite smart outfits such as formal dresses or suits; they will then be covered in messy substances, after which their messy clothes are cut up, typically with scissors, leaving them naked or nearly so.

WAM is sometimes also combined with bondage, where a subject is first restrained or chained up and then hosed down or messed up. Wet and Messy fetishism lends itself well to domination/submission role-playing.

"Cake Sitting" (the act of deliberately sitting on a large cake or gateaux, either clothed or nude) is often considered a sub-fetish in its own right, but may be linked to the Crush fetish. While participants who sit on cakes for pleasure will do so for the tactile sensory experience, or as part of submissive role-playing, those who enjoy watching the act will often focus specifically on the crushing of the dessert as a visual stimulus for a sexual reaction.

Financial domination (also known as money slavery) is a fetish lifestyle, in particular a practice of D/s, where usually a male submissive or "money slave", "pay pig", "human ATM", or "cash piggie" will give gifts and money to a financial female (or male) dominant (also known as "money mistress", "findomme", "money domme", "cash master", "findom").

The relation may often be accompanied by other practices of BDSM and female domination or male domination, like erotic humiliation, but there may be virtually no further intimacy between the individuals. The relationship between the 'slave' and the "mistress" (or "master") may take place solely via online communication, but it is not uncommon that the 'slave' may accompany his mistress while she (or he) is shopping and paying with his (or her) money.

Such a relationship between individuals may be similar to, yet clearly distinguishable from, relationships based on Total Power Exchange. In the latter one, the submissive may grant all his or her money saved and earned to the dominant, in addition with much more aspects of his or her autonomy, but it is not uncommon that both partners have an intimate relationship as well. The fetish of financial domination fetish should also be distinguished by Sugar daddy/Sugar babe-like relations between individuals, where the male may spend gifts and money to 'his' girl, without explicit elements of female domination.

Financial domination is a paraphilia stemming from a devotion of financial slavery or to be dominated in a financial way. Many pro-dommes and femdommes found this to be a natural extension for any professional dominatrix who is already being paid for fetish services, and began to exploit it with clients who shared her fetish. Some domme clients were aroused as much by giving money to a dominant woman, as they were by any fetishes they may have been coming to see her for. The dominatrix may also be aroused from being financially worshipped.

Early online financial domination started with websites such as "The Eurasian Goddess' Altar" and "Princess Sierra". These original sites spawned an explosion of imitators. Today, financial domination has spawned an entire online cult fetish, and type of domination.

As a paraphilia, urine may be consumed or the person may bathe in it. Other variations include arousal from wetting or seeing someone else urinate in their pants or underclothes, or wetting the bed. Other forms of urolagnia may involve a tendency to be sexually aroused by smelling urine-soaked clothing or body parts. In many cases, a strong correlation or conditioning arises between urine smell or sight, and the sexual act. For some individuals the phenomenon may include a diaper fetish and/or arousal from infantilism.

Urolagnia is sometimes associated with, or confused with, arousal from having a full bladder or a sexual attraction to someone else experiencing the discomfort or pain of a full bladder, possibly a sadomasochistic inclination.

One of the earliest descriptions of boots as a fetishistic object can be found in Émile Zola's 1868 novel "Thérèse Raquin". Actual boot fetishism is described in the diaries of 19th-century British woman Hannah Cullwick, of which parts have been published.

Hermine Hug-Hellmuth described boot fetishism scientifically in 1915. This article has also been published in English with comments by Arlene K. Richards in 1990, as "Female fetishes and female perversions: Hermine Hug-Hellmuth's "A case of female foot or more properly boot fetishism" reconsidered".

Boots were used by S. Rachman as a subject for research on conditioning as a cause for fetishism in the 1960s, making men sexually aroused by seeing pictures of boots, but the results have been put into question later, as boots already were very much en vogue for sexually attractive women at the time.

Unlike shoes, boot styles have often appeared as street wear before they inspire fashion designers. Boots are usually seen as a sign of empowerment for the wearer, especially when worn by women. This may be a reason for the connection to BDSM, where boots usually are seen as a statement of dominance. So called boot worship became a common subcultural practice among sadomasochists and related fetishists in the early 20th century.

High-heeled boots help to elongate the calf, creating a longer-legged appearance which is generally considered to be more sexually attractive. The length of the boot shafts also adds to this impression. Boots have been displayed in magazines such as Leg Show and there are also magazines and websites aimed directly at this fetish. Boot fetishism may be accompanied by a fetish for the material from which it is made, such as leather, rubber, or latex. Boot fetishism is often targeted at fashion boots and riding boots but there are also boots expressly made for fetish purposes, such as ballet boots and some forms of thigh-high boots.

There is also a very prominent subsection of mostly gay men who fetishize men's boots, with "boot worship" being a common practice in this group, to the point where there is a yearly contest to see who is the best bootblack. The types of boots favored by men differ from those worn by women, with men typically preferring more sturdy, rugged boots, such as combat boots, jump boots, motorcycle boots, or riding boots. These boots feature prominently in outfits worn by leather enthusiasts in competitions such as International Mr. Leather.

According to Anil Aggrawal, in forensic science, levels of sexual sadism and masochism are classified as follows:

Sexual masochists:

- "Class I": Bothered by, but not seeking out, fantasies. May be preponderantly sadists with minimal masochistic tendencies or non-sadomasochistic with minimal masochistic tendencies

- "Class II": Equal mix of sadistic and masochistic tendencies. Like to receive pain but also like to be dominant partner (in this case, sadists). Sexual orgasm is achieved without pain or humiliation.

- "Class III": Masochists with minimal to no sadistic tendencies. Preference for pain or humiliation (which facilitates orgasm), but not necessary to orgasm. Capable of romantic attachment.

- "Class IV": Exclusive masochists (i.e. cannot form typical romantic relationships, cannot achieve orgasm without pain or humiliation).

Sexual sadists:

- "Class I": Bothered by sexual fantasies but do not act on them.

- "Class II": Act on sadistic urges with consenting sexual partners (masochists or otherwise). Categorization as leptosadism is outdated.

- "Class III": Act on sadistic urges with non-consenting victims, but do not seriously injure or kill. May coincide with sadistic rapists.

- "Class IV": Only act with non-consenting victims and will seriously injure or kill them.

The difference between I–II and III–IV is consent.

As the Internet becomes more widely available to deliver pornographic material, the bondage magazine market began to decrease. As of 2003, specialist bondage magazines were mostly displaced by bondage material on the Internet, and bondage imagery is to be found in mainstream pornographic magazines, such as "Nugget" and "Hustler"'s "Taboo" magazine.

However, the tradition of bondage magazines continues in the form of "art books" of bondage photographs, published by mainstream publishers such as Taschen.

Certain websites have begun providing bondage videos and photographs featuring the kidnapping roleplay, which has been largely the hallmark of "detective" style bondage magazines. These styles are much closer to the style of bondage scenes in mainstream television.