BDSM actions embrace a broad range of practices. There are more common activities, for example, rope bondage and flogging (use of multi-tailed whip) to rarer fetishes . The wide variety of BDSM activities, as shown in Table 4, can be divided into impact play, sensation play, rough body play, genitals, sex and bodily fluids, sensory deprivation, bondage, scene or relationship dynamics, role play and psychological play, and body modification . Although penetrative sex acts can be included in BDSM play, sexual intercourse does not necessarily occur . Physical health complications such as bruising and musculoskeletal injuries due to whipping, spanking, and flogging; broken skin leading to infections or nerve damage due to bondage or handcuffs; burns due to hot wax play; blood-borne pathogen exposure due to needling or temporary piercings; fainting due to vasovagal response to pain; and emotional intensity may occur in BDSM plays . Wiseman , a prominent BDSM community author, explains in his BDSM beginner’s book SM 101: A Realistic Introduction the risk of breath control play and clarifies that practitioners can be taught how to participate in such activities safely. However, the health risks of breath play can never be eliminated. Edge plays are BDSM activities with a high physical or psychological risk. Sexual asphyxia or breath control play can be named as one of them. Breath control play is very controversial in the BDSM scene, and some BDSM communities ban members from engaging in breath control play . In general, BDSM practitioners seem to be well informed on potential injuries. Still, 44% of interviewed practitioners have consulted a medical professional for BDSM-related matters. Because of fear of discrimination, BDMS practitioners tend not to seek medical advice, when it is needed .
The fatal outcome in BDSM play seems to be very rare. There are 14 published case reports and one organized study on non-natural death associated with sexual activity. The study by Bunzel et al. showed that of 16,437 autopsies from 1993 to 2017, 0.018% (3 cases) were non-natural deaths related to sexual activity involving BDSM. On the other hand, 0.13% of cases were non-natural deaths in autoerotic practices . Similar numbers of autoerotic fatalities can be found in other studies conducted in Germany (0.1%)  or Canada (0.2%) . The incidences of autoerotic deaths per million inhabitants per year have been reported to be 0.3 in Australia and 0.14 in Sweden , 0.5 in Germany , and 0.2–0.5 in Canada . The results of Bunzel et al. on BDSM fatalities can provide a rough point of reference for the incidence of fatal outcome in BDSM play .
As for natural death related to sexual activities, a 45-year mortality study conducted in Germany showed a rate of 0.26%. The men’s mean age was 57.2 years, and the women’s mean age was 45 years. The most common cause of death was coronary heart disease, followed by myocardial infarction and reinfarction . A few cases are described on natural death in association with autoerotic activities [23,24,25,26], but no cases on natural death connected to BDSM play. A reason might be the age of BDSM practitioners. People under the age of 50 years tend to be more interested in BDSM activities than the older population [4, 27]. This seems to correspond with the mean age of the here presented cases, which was 34.9 years.
Causes of death
The most prominent cause of death in BDSM fatalities emerging from the 17 reported cases was strangulation (88.2%). It can be differentiated between ligature and manual strangulation and hanging; ligature strangulation was documented as the most frequent cause of death. In one case, the cause of death was severe hemorrhage caused by the vaginal insertion of foreign objects . Strangulation followed by intoxication is also the most frequent cause of death in the course of autoerotic practices [8, 21]. Traumatic injury, perforation, and electrocution are named as other causes of death in autoerotic fatalities, but they are rarer than strangulation .
Care is necessary when describing different causes of asphyxia and in particular strangulation. In two cases [9, 10], the deceased was strangulated with hands by the partner. The authors described the causes of death strangulation as sexual choking. The usage of the term choking in this context is incorrect, as choking by definition is asphyxia by obstruction of the air passage and not external pressure applied on the neck . Sexual choking with hands should better be described as strangulation with hands and therefore as a form of manual strangulation. In the compared cases, the classification of asphyxia and also the definitions of subtypes were not consistent. The model of classification and definitions by Sauvageau and Boghossian  was used to compare the different cases and leads to the results we presented in this review. The definitions of the subtypes of asphyxia are described in Table 1. It is important when describing BDSM fatalities to use forensic terminology and definitions and not general BDSM terms.
A difficulty concerning BDSM fatalities is the forensic case work with the aim to reconstruct the fatal event. Especially in these delicate situations, to prevent misinterpretations, the forensic experts must have in mind that the original situation of the fatality could have been changed. Except for medical interventions like resuscitation measures by the partner and/or medical professionals, it is possible that the partner could have changed certain features of the scene, e.g., because of feeling ashamed or being afraid of the possible consequences. Sex toys and other BDSM equipment could have been removed or the other person could have even mimicked an autoerotic death and fled the scene. Mostly, there are no other witnesses than the probably shocked sexual partner who is not able or does not want to give a detailed explanation of the situation. Statements of the present participant(s) can be inexact or contradictory due to emotional stress after witnessing the other person’s death . Also, incorrect shame-associated statements from relatives about the deceased’s sexual behavior or interest in BDSM can lead to wrong conclusions . In two of the described cases, there were various video materials found on the deceased’s computers [9, 10]. The films contained breath control play of hetero- and homosexual partners as well as autoerotic practices. Such videos material on BDSM activities can offer assistance to reconstruct fatal events. Therefore, forensic experts should search for electronic or printed material on BDSM activities as well as hidden cameras at the scene.
The use of alcohol and drugs can play a relevant role in sexual activity. In 58% of autoerotic fatalities, the toxicology reports were negative or a therapeutic presence of drugs was found . Bunzel et al. report only 36% negative toxicology reports for autoerotic fatalities and could not confirm the use of nitrites (poppers) in any case . An online, cross-sectional global drug survey with 22,289 responses reported alcohol as the most common drug to have sex on, followed by cannabis and MDMA. For homosexual men, the fourth most frequently drug used was poppers, while in the other groups (heterosexual men, homosexual and heterosexual women) it was rarely reported . BDSM communities disclaim the use of drugs and alcohol during plays. Drugs and alcohol can affect the practitioner’s ability to participate in a BDSM play with the needed safety precautions . Wiseman states that performing BDSM activities while being drunk or on drugs is unsafe and irresponsible . The use of mind-altering substances during BDSM play is controversially discussed within the BDSM communities, and many BDSM organizations have specific rules against the use of substances . In only 13 of the 17 described cases, a toxicology report for the deceased was mentioned. In 8 of the 13 cases (61.5%), the toxicology analysis was positive. These results show that fatalities correlate with the usage of alcohol and drugs. The numbers correspond with the results from Bunzel et al. for autoerotic fatalities .
BDSM communities and safeguards
In 9 cases, the deceased and the partner were not novices to BDSM activities. In two of these cases, the partner was a dominatrix. In three cases, instructions were given, and cardiopulmonary resuscitation was discussed before starting BDSM play. In all three cases, cardiopulmonary resuscitation was performed by the partner. Our results show that despite being informed about BDSM activities and the presence of medical knowledge, BDSM play can still have a fatal outcome. In the USA, about 85% of the BDSM practitioners said that they received some of their BDSM education from a mentor of the scene, whereas only about 9% stated that they did not gain their knowledge from a mentor directly. Of 1405 asked BDSM practitioners in the USA, 79% belonged to a BDSM organization [29, 30]. BDSM communities developed clear ethical values and guidelines to minimize risk and create an effective way of mentoring and educating novices to BDSM. They offer classes and workshops on dungeon (public or private place for BDSM gatherings) safety, how to classes on techniques and skills, setting the scene, or negotiation and aftercare, to mention just a few . Meetings for novice practitioners contain basic first aid information and more specialized information such as changes in breathing patterns and how to handle emergencies .
BDSM practitioners use a safeword, a prearranged word, or a gesture that can be signaled by one of the practitioners with the wish to end the play. It is a way to communicate the physical and emotional discomfort . This is part of the overall principle in the BDSM scene, which is referred to as safe, sane, and consensual (SSC). The term risk-aware consensual kink (RACK) is preferred by certain BDSM practitioners, as it does not use the word “sane,” which can implicate negative stereotypes . Also, there exists a universal safeword system called the “traffic light” system with the opportunity to point out whether the intensity is great (green), slowing down (yellow), or stopping the play (red). A standardized safeword system has the benefit that it can be used as a “house safeword” in most of the BDSM communities . BDSM communities attach great importance to education and mentoring, and therefore, educational components are a significant part of the organization’s activities [29, 33]. It was not possible to show a correlation between the agreement on a safeword and fatal outcome with our results. In only one case, it was mentioned that no safeword was used; in all other cases, it was not noted.
In two cases, the deceased was a client of a dominatrix . Professional dominatrices provide their services in private dungeons. Male professional dominants are rare . Only a few professional dominatrices offer intercourse, oral sex, or manual gratification to their clients . Professional dominatrices gain their knowledge and BDSM training, mainly by “hands-on” mentoring . They have to learn to minimize psychological and physical risks and how to react if psychological reactions or physical and medical issues occur [34, 36]. Professional dominatrices are well aware of the risks of BDSM plays and acquire knowledge about their client’s physical and psychological responses . Organizations within the BDSM scene offer classes on these topics specifically for professional dominatrices .
It can be agreed with Lee et al. that “(…) it is inaccurate to characterize all BDSM activities as extremely dangerous games.” Safeguards exist, and fatalities can be prevented if they are followed . Our results show that strangulation in the course of erotic asphyxiation is the most common cause of death in fatal BDSM play. BDSM practitioners should be aware of the potential risks in erotic asphyxiation practices. We emphasize to have an emergency or backup plan when practicing BDSM, for example, to have specific tools close at hand to free participants from bondage constructions or the option to quickly bring in another person when needed. We share the opinion about the importance to include accurate information about the risks of BDSM activities in sexual education as an attempt to prevent these fatalities. People should understand the potential risk of unsafe BSDM play, including the danger of combining alcohol or drugs and BDSM activities and that it is essential to learn how to avoid fatal incidents when participating in such activities [8, 12].