Men who have sex with men or males who have sex with males (MSM) refers to men who engage in sexual activity with other men, regardless of how they identify themselves; many choose not to accept social identities of gay or bisexual. The term was created in the 1990s by epidemiologists in order to study the spread of disease among men who have sex with men, regardless of identity.
MSM is often used in medical literature and social research to describe such men as a group for clinical study without considering issues of self-identification.
The term had been in use in public health discussions, especially in the context of HIV/AIDS, since 1990 or earlier, but the coining of the initialism by Glick et al. in 1994 "signaled the crystallization of a new concept." This behavioural concept comes from two distinct academic perspectives. First, it was pursued by epidemiologists seeking behavioral categories that would offer better analytical concepts for the study of disease risk than identity-based categories (such as "gay", "bisexual", or "straight"), because a man who self-identifies as gay or bisexual is not necessarily sexually active with men, and someone who identifies as straight might be sexually active with men. Second, its usage is tied to criticism of sexual identity terms prevalent in social construction literature which typically rejected the use of identity-based concepts across cultural and historical contexts.
MSM are not limited to small, self-identified, and visible sub-populations. MSM and gay refer to different things: behaviors and social identities. MSM refers to sexual activities between men, regardless of how they identify, whereas gay can include those activities but is more broadly seen as a cultural identity. Homosexuality refers to sexual/romantic attraction between members of the same gender and may or may not include romantic relationships. Gay is a social identity and is generally the preferred social term, whereas homosexual is used in formal contexts, though the terms are not necessarily interchangeable. Men who are non-heterosexual or questioning may identify with all, none, a combination of these or one of the newer terms indicating a similar sexual, romantic, and cultural identity like bicurious.
In their assessment of the knowledge about the sexual networks and behaviors of MSM in Asia, Dowsett, Grierson and McNally concluded that the category of MSM does not correspond to a single social identity in any of the countries they studied. There were no similar traits in all of the MSM population studied, other than them being males and engaging in sex with other men.
The term's precise use and definition has varied with regard to transwomen, people born either biologically male or with ambiguous genitalia who now identify as female. Some sources consider transwomen to be MSM, others considering transwomen "along side" MSM, and others are internally inconsistent (defining transgender women to be MSM in one place but referring to "MSM and transgender" in another).
Since LGBT people began to organize for what they saw as their social and legal rights, access to equal heath care has remained an important but often not primary issue. LGBT-specific health organizations including charities educating on specific issues, health clinics, and even professional organizations for LGBT people and allies have formed. Many of them have advocated for specific changes to various governmental practices and the ongoing effort to legalize same-sex marriage often includes examples of LGBT people unable to secure identical health coverage as that of their heterosexual counterparts.
Since medical literature began to describe homosexuality, it has often been approached from a view that sought to find an inherent psychopathology as the root cause. Much literature on mental health and homosexuals centered on their depression, substance abuse, and suicide. Although these issues exist among non-heterosexual men, discussion about their causes shifted after homosexuality was removed from the Diagnostic and Statistical Manual of Mental Disorders in 1973. Instead, social ostracism, legal discrimination, internalization of negative stereotypes, and limited support structures indicate factors homosexuals face in Western societies that often adversely affect their mental health.
Sex has many health benefits, including relieving stress, boosting the immune system with higher levels of immunoglobulin A, improving cardiovascular health, increasing self-esteem, improving intimacy, reducing pain by production of the hormone oxytocin, reducing the risk of prostate cancer, strengthens pelvic muscles, and promoting good sleep. Sexual behavior can be a disease vector. All human sexual behavior that involves contact with the bodily fluids of another person is considered to have some risk of transmission of sexually transmitted infections (STIs). Although the likelihood of transmitting infection varies a great deal by activity, in general all sexual activities between two (or more) people is considered a two-way route for the transmission of STIs; "giving" or "receiving" are both risky, although receiving carries a higher risk. Safe Sex immensely reduces the risk of STI/STD infections. Condoms, particularly latex, greatly reduce the risk of getting or passing on many STDs (including HIV) in either anal or oral sex. Safe sex is a relevant harm reduction philosophy. A 2007 study reported that two large population surveys found "the majority of gay men had similar numbers of unprotected sexual partners annually as straight men and women." With MSM, there are two main forms of sexual activity that carry greater risks, anal and oral sex, although not all MSM engage in them. MSM may also have greater risks in that they can switch sex roles.
Historically, anal sex has been popularly associated with male homosexuality and MSM. However, many MSM do not engage in anal sex. Among those who do have anal sex, the insertive partner is referred to as the top or active partner. The man being penetrated is referred to as the bottom or passive partner. Preference for either is referred to as versatile.
Anal sex most often refers to the sex act involving insertion of the penis into the anus. The term anal sex can also sometimes include other sexual acts involving the anus, including but not limited to anilingus and fingering. It is a form of sexual behavior considered to be comparatively high in risk, due to the vulnerability of the tissues and the septic nature of the anus. As the rectal mucosa provides little natural lubrication, a personal lubricant is often required or preferred when penetrating the anus.
Oral sex refers to sexual activities involving the stimulation of the genitalia by the use of the mouth, tongue, teeth or throat. Fellatio and irrumatio refer to oral sex performed on a man. Analingus refers to oral stimulation of a person's anus. Oral stimulation of other parts of the body (as in kissing and licking) is usually not considered oral sex. People may engage in oral sex as part of foreplay before sexual intercourse, or during or following intercourse. It may also be performed for its own sake. Oral sexual activities are not effective methods of preventing sexually transmitted diseases (STDs), although some forms of STD are believed to be less easily spread in this way.
Some receivers regard receiving oral sex as an ego boost, believing that such an act is a form of dominance over their sexual partner because of the overt submissive nature of the act; the giver may often be on their knees before the receiver to perform the act of pleasure. In ancient Greece, fellatio was referred to as "playing the flute"; the Kama Sutra has a chapter on oparishtaka, or "mouth congress".
A sexually transmitted disease (STD), also known as a sexually transmitted infection (STI), is an illness that has a significant probability of transmission between humans by means of sexual contact, including oral sex and anal sex. STI has come to be preferred, as it has a broader range of meaning; a person may be infected, and may potentially infect others, without showing signs of disease. Many STDs are (more easily) transmitted through the mucous membranes of the penis, rectum, urinary tract, and (less often, depending on type of infection) the mouth, throat, respiratory tract and eyes. The visible membrane covering the head of the penis is a mucous membrane, though it produces no mucus (similar to the lips of the mouth).
Mucous membranes differ from skin in that they allow certain pathogens into the body. Pathogens are also able to pass through breaks or abrasions of the skin, even minute ones. The shaft of the penis is particularly susceptible due to the friction caused during penetrative sex. The primary sources of infection in ascending order are venereal fluids, saliva, mucosal or skin (particularly the penis); infections may also be transmitted from feces, urine, and sweat. The amount required to cause infection varies with each pathogen, but likely is less than can be seen with the naked eye.
Although mucous membranes exist in the mouth as in the genitals, many STIs seem to be easier to transmit through oral sex than through deep kissing. According to a safe sex chart, many infections that are easily transmitted from the mouth to the genitals (or from the genitals to the mouth) are much harder to transmit from one mouth to another. With HIV, genital fluids happen to contain much more of the pathogen than saliva. Some infections labeled as STIs can be transmitted by direct skin contact. Herpes simplex and HPV are both examples. KSHV, on the other hand, may be transmitted by deep-kissing, but also when saliva is used as a sexual lubricant.
As may be noted from the name, sexually transmitted diseases are transmitted from one person to another by certain sexual activities rather than being actually caused by those sexual activities. Bacteria, fungi, protozoa or viruses are still the causative agents. It is not possible to catch any sexually transmitted disease from a sexual activity with a person who is not carrying a disease; conversely, a person who has an STD got it from contact (sexual or otherwise) with someone who had it or with their bodily fluids. Epidemiological studies have investigated the networks that are defined by sexual relationships between individuals, and discovered that the properties of sexual networks are crucial to the spread of sexually transmitted diseases. In particular, assortative mixing between people with large numbers of sexual partners seems to be an important factor. It is also possible to be an asymptomatic carrier of sexually transmitted diseases.
Acquired immune deficiency syndrome (AIDS) is a disease of the human immune system caused by the human immunodeficiency virus (HIV). HIV can infect anybody, regardless of sex, ethnicity, or sexual orientation. Worldwide, an estimate 5-10% of HIV infections are the result of men having sex with men.
In MSM, this transmission can involve anal or oral sex, blood transfusion, contaminated hypodermic needles, or other exposure to one of the above bodily fluids. Regardless of the gender of the receptive partner, anal sex carries a higher risk of infection than most sex acts, but most penetrative sex acts carry some risk. The main route of transmission is through unprotected sex. Properly used condoms can reduce this risk. The adult prevalence rate in the United States is 0.7%, with over 1 million people currently living with HIV. In the United States from 2001–2005, the highest transmission risk behaviors were sex between men (40–49% of new cases) and high risk heterosexual sex (32–35% of new cases). HIV infection is increasing at a rate of 12% annually among 13-to-24-year-old American men who have sex with men. Experts attribute this to "AIDS fatigue" among younger people who have no memory of the worst phase of the epidemic in the 1980s and early 1990s, as well as "condom fatigue" among those who have grown tired of and disillusioned with the unrelenting safer sex message. The increase may also be because of new treatments. In developing countries, HIV infection rates have been characterized as skyrocketing among MSM. Studies have found that less than 5% of MSM in Africa, Asia, and Latin America have access to HIV-related health care.
Hepatitis B is a disease caused by hepatitis B virus which infects the liver of hominoidae, including humans, and causes an inflammation called hepatitis. The disease has caused epidemics in parts of Asia and Africa, and it is endemic in China. About a third of the world's population, more than 2 billion people, have been infected with the hepatitis B virus. Transmission of hepatitis B virus results from exposure to infectious blood or body fluids containing blood. Possible forms of transmission include (but are not limited to) unprotected sexual contact, blood transfusions, re-use of contaminated needles and syringes, and vertical transmission from mother to child during childbirth. HBV can also be transmitted between family members within households, possibly by contact of nonintact skin or mucous membrane with secretions or saliva containing HBV. However, at least 30% of reported hepatitis B among adults cannot be associated with an identifiable risk factor.
MSM have an increased incidence and prevalence of STIs including Kaposi's sarcoma-associated herpesvirus and syphilis. This follows an increase in STDs among men who have sex with men in the U.S..
Syphilis (caused by infection with Treponema pallidum) is passed from person to person through direct contact with a syphilis sore, which occur mainly on the external genitals or in the vagina, anus, or rectum. Sores also can occur on the lips and in the mouth. Transmission of the organism occurs during vaginal, anal, or oral sex. In 2006, 64% of the reported cases in the United States were among men who have sex with men. This is consistent with a rise in the incidence of Syphilis among MSM in other developed nations, attributed by Australian and UK authors to increased rates of unprotected sex in the MSM community.
Genital human papillomavirus (HPV) is a common virus that most sexually active people in the U.S. will have at some time in their lives. It is passed on through genital contact and is also found on areas that condoms do not cover. Most men who get HPV of any type never develop any symptoms or health problems. Some types of HPV can cause genital warts, penile cancer, or anal cancer. MSM and men with compromised immune systems are more likely than other men to develop anal cancer. Men with HIV are also more likely to get severe cases of genital warts that are hard to treat.