Teenagers who are gay, lesbian, or bisexual (GLB) are overwhelmingly similar to their non-GLB peers. However, because of societal stigma or potential rejection,these adolescents may face various challenges during their adolescent years and are at greater risk for substance abuse, depression, suicide, and sexually transmitted diseases (STDs) than their peers who are heterosexual. The first contact with a professional in the medical field for the teenager who is GLB is often the pediatrician, family practitioner, or internist. Many healthcare professionals provide medical care to teenagers who are GLB far more often then they realize. The practitioner's knowledge and sensitivity regarding sexuality issues strongly influences the patient's comfort level in seeking optimal health care in the future.
In the 1950s, Kinsey conducted the first modern sexuality studies. He concluded that by the time an individual is aged 20 years, nearly 28% of young men and 17% of young women had at least one homosexual experience. Approximately 10% of those polled considered themselves to be predominantly homosexual. [1, 2] In 1993, Diamond and colleagues performed a review of studies conducted with various populations and concluded that the prevalence of predominant homosexual attraction was lower than Kinsey had predicted.  Diamond concluded that 5-6% males and 2-3% females considered themselves to be GLB.
Today, most studies regarding the prevalence of homosexuality involve adult subjects (5-10%), but these figures also appear to be consistent with the available data concerning adolescents.
In 1990, Ramafedi et al conducted the Demography of Sexual Orientation in Adolescents study.  Using the Minnesota Adolescent Health Survey, they polled 34,706 middle and high-school students from diverse socioeconomic and cultural groups in Minnesota. Researchers included 5 items: sexual fantasies, behaviors, attractions, behavioral intent, and labeling of sexual orientation. Data revealed that the percentage of teenagers reporting primarily GLB attractions increased with age (6.4% when aged 18 y), and uncertainty of sexual orientation decreased with age (8.9% when aged 18 y). Fewer than 33% of subjects with predominantly homosexual fantasies, attractions, or behaviors actually identified themselves as homosexual or bisexual. These figures suggests that most adolescents who might be experiencing same-sex attractions are reluctant to label themselves as GLB.
Modern research on this topic reinforces the idea that sexuality is a dynamic construct that should be understood as a combination of sexual attractions, sexual behaviors, and sexual identity. Adolescents who experience same gender attractions and behaviors more commonly label themselves as heterosexual than label themselves as homosexual. Therefore, the sensitive practitioner is likely to obtain more honest information from their teen patients if they inquire about sexual activity and attractions rather than to ask the teen to label themselves as GLB. 
Theories About Gay, Lesbian, and Bisexual Sexuality
No specific biological or psychosocial factors have been identified that determine why some individuals develop sexual attraction toward members of the same sex. For decades, researchers have asked the question of whether biological or social factors play the greater role in development of sexual attraction, without reaching a consensus. Freud's theory attributes homosexual development in males to a family unit in which the adolescent has a strong relationship with his mother and a conflicted hostile relationship with a domineering father. According to this theory, the outcome of this classic unit is failure by the adolescent to resolve critical psychosexual issues, leading to the development of homosexual attractions and identity. No data document the validity of the above theory of gay, lesbian, or bisexual (GLB) sexuality made many years ago.
Biological theories regarding GLB sexuality attempt to link sexual orientation with DNA markers on the X chromosome or to demonstrate that in utero maternal hormones have an effect on sexual orientation. Other theories attempt to show that the brain of the male who is GLB is anatomically different from that of the male who is heterosexual. Studies show a concordance of sexual orientation in male twins who are raised apart, lending support to the idea that biological factors greatly contribute to the development of sexual orientation. Likewise, Bell and colleagues conducted a study of 1500 individuals identified as gay and lesbian through detailed interviews involving various aspects of their childhood environment, including parental relationships.  They concluded that adults who are GLB and adults who are heterosexual had almost identical familial and sociological upbringing.
To date, research studies suggest that aspects of homosexuality are likely linked to genetic factors.
Developmental Stages of Gay, Lesbian, and Bisexual Adolescents
Teenagers who are gay, lesbian, or bisexual (GLB) are overwhelmingly similar to their peers who are heterosexual in overcoming the regular struggles of adolescence. However, they may face additional challenges from parents, religious leaders, and friends who do not accept homosexuality. Trying to keep their sexuality hidden from close friends and family members can lead to a profound sense of isolation. Unfortunately, some teenagers have little access to positive information regarding their homosexuality, and other teenagers are unwilling to obtain information for fear of being discovered.
In 1988, Troiden published a framework for understanding the developmental processes experienced by adolescents who are GLB.  These milestones are not age-specific but constitute a general guide to comprehending the experiences of teenagers who are GLB as they become aware of their sexual inclinations.
Stage 1 - Sensitization
Many persons who are GLB recall feelings of being different from their peers of the same sex during early and middle childhood. Such feelings were nonspecific and nonsexual in nature.
Stage 2 - Identity confusion
During early and later adolescence, sexual attraction toward members of the same sex begins, often occurring with the absence of attraction toward the opposite sex. Some teenagers who are GLB start sexual experimentation. Over the past 10 years, the Internet has emerged as a significant resource for these adolescents, as they can enter chat rooms to network and share concerns with other teenagers who are GLB without having to disclose their identity. Although the teen may view anonymity as a benefit, the use of these Internet chat rooms can lead to risky sexual practices or even to sexual exploitation by adult predators.
Teenagers in this developmental phase may try to deny or change their homosexual feelings; some may display outward hostility toward persons who are GLB, sometimes to the point of harassment or violence. This distancing from the acceptance of sexual orientation is termed dissociation, and acting "macho" to the level of antisocial behavior is termed signification. Obviously, these actions are used as a way of hiding an individual's own feelings.
Teenagers who have identified themselves as homosexual, or having same-sex attraction, are at higher risk for depression, substance abuse, and suicide attempts. Teenagers who deny their homosexuality or bisexuality to the outside world (ie, "in the closet") expend tremendous amounts of energy hiding and denying their sexual inclinations; some may channel much of their energies into excelling in academics, athletics, or other endeavors.
Stage 3 - Identity assumption
This stage, in which teenagers begin to define themselves as GLB, occurs during late adolescence (aged 18-21 y). Adolescents may disclose their sexual orientation to their friends, or they may have several discrete sets of friends, including a set that is aware of their orientation and another set that is not aware. Occasionally, the teen may cultivate an extensive network of online friends, who consist of other teenagers who are GLB who communicate almost exclusively through Internet chat rooms. This online community can provide both support as well as a forum in which the teen can "test the waters" of coming out. 
Whether they disclose their sexuality (ie, "come out") voluntarily or are discovered, teenagers who are GLB are at risk of rejection from peers and family members, which makes them more likely to run away from home. Adolescents who are exposed to harassment and physical abuse in school are most likely to drop out of school. In some instances, teenagers who are GLB may be expelled from their homes, placing them at higher risk of prostitution and substance abuse. Resourceful teenagers may begin to associate with other persons who are GLB in support groups or social settings.
Stage 4 - Commitment
As teenagers who are GLB reach young adulthood, many realize acceptance of self and identify more with the community of individuals who are gay. Disclosure to family members usually occurs during this period. Once a young adult has accepted his or her sexual orientation, relationships with true intimacy become a more likely possibility.
Role of the Pediatrician in Caring for Gay, Lesbian, and Bisexual Patients
The role of the pediatrician is to provide a safe and confidential environment in which adolescents feel free to discuss issues of sexuality, mental health, and substance abuse. Clinicians must develop a comfortable manner when asking adolescents about sexuality, phrasing questions in a nonjudgmental and open-ended fashion. For example, asking, "Are you dating anyone?" is preferable to asking, "Do you have a girlfriend?" If a pediatrician feels reluctant or unable to ask questions and support adolescents who are gay, lesbian, or bisexual (GLB), he or she is obliged to make a referral to a colleague or another professional who has personal comfort and experience in this area. Conversely, physicians who are comfortable caring for teenagers who are GLB should be sure to refer subspecialty physicians who are likewise comfortable working with these patients, when indicated. 
Disclosure of a teenager's homosexuality by a health professional to his or her parents without the teenager's permission is a violation of confidentiality. Such disclosures may lead to catastrophic consequences in the teenager's life, including depression and suicide, physical and emotional abuse, and homelessness. A provider who is unable to offer confidential care to a patient who is GLB must refer the patient to another provider without informing the parent of the sexual orientation of the teenager. 
The American Academy of Pediatrics recommends that pediatricians who care for teenagers understand the unique medical and psychosocial issues facing youth who are GLB. [10, 11] A working knowledge of the terms describing the sexuality of an individual is also important. Below are a number of definitions that may be used to help clarify various aspects of sexuality. 
Sexual orientation - Persistent patterns of sexual and emotional arousal toward persons of either the same, opposite, or both sexes
Gender identity - An individual's innate knowledge of being male or female, which generally is established by the time an individual is aged 3 years
Homosexual – An individual whose patterns of sexual and emotional arousal are toward members of the same sex (eg, gay, lesbian)
Heterosexual – An individual whose patterns of sexual and emotional arousal are toward members of the opposite sex (eg, straight)
Bisexual – An individual whose pattern of sexual and emotional arousal is toward members of both sexes
Transgendered- An individual who believes that his or her innate gender is different from his or her biologically determined gender
Transvestite - An individual who derives sexual pleasure or comfort from dressing in clothing of the opposite sex; behavior often independent of the individual's sexual orientation
In the closet - Denial of homosexuality or bisexuality to the outside world
Coming out - Process of self-acceptance and public disclosure of one's homosexual orientation
Gender role - Outward expression of masculinity or femininity; often independent of one's sexual orientation
Remember that GLB teenagers share the same goals, dreams, values, worries and fears as their heterosexual peers. The risk increased mental and physical health risks often result from perceptions of peer, family and/or societal non-acceptance of their sexuality.
Inquire about specific sexual practices, such as mutual masturbation, oral sex, anal sex, and condom use. Knowing if the patient is the insertive ("top") or receptive ("bottom") partner in oral and anal sex is important in determining infectious disease risks and testing needs.
Discuss unsafe sexual practices and high-risk situations, such as frequent sexual contacts with little-known partners and sexual activity in unknown locations, as well as the dangers of concurrent use of alcohol and drugs. Remember that teenagers who identify as gay, lesbian, or bisexual (GLB) may also be heterosexually active.
Inquire about the use of illegal substances, specifically asking about "club drug" use. Some older adolescents who are GLB may attend "circuit parties" with other youth who are GLB. These parties often involve the use of methylenedioxymethamphetamine (MDMA), also called ecstasy; methamphetamine, gamma-hydroxybutyrate (GHB); and others. As is common in adolescence, teens often assume that these substances are safe to use and do not comprehend their lethality. GLB patients who are suspected of using these substances should be counseled and referred to the appropriate substance abuse treatment programs.
Ascertain the risk of suicide and depression. 
Teenagers who are GLB can be ostracized or even expelled from their homes, leading to a significantly increased risk of prostitution and substance abuse.
Teenagers who are GLB may be guilt ridden and feel that they always will be limited personally and professionally by their sexuality.
Approximately 30-40% of teenagers who are GLB attempt suicide at least once.
Approximately one third of those teenagers who attempt suicide do so within 1 year of identifying their homosexuality.
Other risk factors for suicide by teenagers who are GLB include family conflict (44%), interpersonal issues regarding sexual orientation (33%), relationship problems (19%), and substance abuse (85%).
Recent data suggest that adolescent males who are uncertain of their sexual orientation may have increased body image dissatisfaction. The pediatrician should screen for these thoughts because they can lead to disordered eating obsessions and behaviors. 
Sexually transmitted diseases (STDs) and adolescents who are lesbian
- In general, these adolescents are at a decreased risk for STDs.
- Inquire about any heterosexual or bisexual activity of the teenager or her partners, as this activity may place the teenager at risk for other STDs.
- Older lesbian adolescents and young adults need routine gynecological screening for human papilloma virus (HPV) infection because they may have had heterosexual contact with a male in the past which could put them at risk.
STDs and male adolescents who are gay
- Perform a thorough examination of the mouth, anus, and rectal area for signs of venereal lesions.
- Gonorrhea can be urethral, pharyngeal (often asymptomatic), or anorectal (which can present with rectal pruritus, tenesmus, pain, and/or bleeding).
- Chlamydial infections are often urethral and anorectal (oropharyngeal chlamydia is rare).
- Lymphogranuloma venereum may cause anorectal complications, involving edema, and the presence of red friable mucosa in the distal anus. Further complications include fistula, abscess, and stricture formation.
- Primary syphilis presents as chancres around the anus, pharynx, mouth, and penis. Secondary syphilis presents as a diffuse rash, which may be mistaken for pityriasis rosea. Prior to making a definitive diagnosis of pityriasis rosea, testing for syphilis is especially indicated for any male who is having sex with other males.
- Herpes simplex I and II manifest as ulcers in the mouth, pharynx, and anus. Anoscopy may demonstrate pus and ulceration. Complications of peritonitis are possible.
- Genital warts occur on the genitals, oropharynx, perianal area and anal canal.
- Mouth-to-anus contact (ie, rimming) is a common route of infection.
- Bacterial pathogens include Shigella species and Campylobacter jejuni. Infections may present with diarrhea, pus, and blood in stools, accompanied by chills and fever.
- Parasitic pathogens include Entamoeba histolytica and Giardia lamblia. Symptoms include gas, cramping, and flatus.
- Viral infections include hepatitis A, hepatitis B, hepatitis C, and hepatitis D. Hepatitis A is transmitted via fecal-oral route, whereas hepatitis B, hepatitis C, and hepatitis D are acquired through sexual penetration intercourse. Hepatitis A and hepatitis B vaccines are recommended for all adolescents who are sexually active.
- Rectosigmoid tears may result from foreign body insertion, "fisting" (insertion of a hand into the anus), or vigorous anal intercourse.
- Allergic proctitis is secondary to lubricants and douches, especially when scented or colored products are used. Patients are advised to discontinue use of products if allergic reactions occur.
- Penile edema results from frequent or vigorous intercourse. The use of penile rings may result in ecchymoses and edema.
- Contact dermatitis may develop from use of lubricants and latex.
Human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) 
- Most adolescents infected with HIV are asymptomatic when they are diagnosed via an HIV-screening program or physician.
- Some early manifestations of HIV disease include chronic lymphadenopathy, weight loss, fatigue, recurrent tinea infections, severe molluscum contagiosum, and leukopenia.
- Advanced presentations of AIDS manifest as opportunistic infections. These infections do not typically occur unless the CD4+ count is 500/µL or lower. The clinician should suspect a possible diagnosis of AIDS if the patient presents with the following symptoms (without a clear etiology): chronic cough and shortness of breath, persistent fevers, persistent diarrhea, dysphagia, newly onset neurological impairment, severe herpes zoster infection, severe thrush, chronic recurrent respiratory infections, or infection anywhere with an atypical pathogen.
For males who are having sexual contact with males, the Centers for Disease Control and Prevention (CDC) recommends annual screening for all sexually active males and more frequent screening (every 3-6 mo) for males who have multiple partners and for those using illicit drugs. 
Urethra - Nucleic acid amplification test (NAAT) urine analysis (or culture) for gonorrhea and chlamydia
Oropharynx - Culture or NAAT for gonorrhea
Anorectal area - Culture or NAAT for gonorrhea and chlamydia
Ova and parasite studies for parasitic pathogens if GI symptoms present
Hepatitis A, hepatitis B, and hepatitis C antibodies
HIV antibody testing, performed with counseling and confidentiality
Anal Papanicolaou test: Currently, no expert consensus supports the use of anal Papanicolaou testing for oncogenic human papilloma virus infection. However, this may be a consideration in patients with HIV or a history of anorectal warts.