Puberty and sexual development mark a normal stage of life during which adolescents experience many physical, cognitive * , and emotional changes.
“Mostly I'm pretty scared because I don't know if I'm normal or, you know, just strange. My body seems to be changing but not like some of my friends. I still look pretty much like a little kid and my best friend looks like he's 18 or something. I don't want to go near the gym anymore because then I'll have to take a shower. I know the other guys are going to laugh at me because I, well, you know, just don't look developed.”—John, age 13.
“Now I have zits all over my face, my nose is too big, and my breasts are too small. It really bothers me. I don't think guys will ever notice me, let alone like me if my body stays like this—I'm a disaster.”— Dominique, age 14.
“No one had told me anything about menstruation. When I started to bleed and nobody was at home, I got so scared I called 911.”—Aisha, age 12.
During adolescence the body a child has had for several years seems to become different and sometimes strange. This phase of development is referred to as puberty and involves rapid changes in the body, including sexual maturation. Bodies, attitudes about self and others, thinking abilities, and interest in sexual activities change. The good news is that puberty does not last forever. Most people get through it by age 18.
Adolescence in Western societies ranges from about 8 to 20 years of age. During this period there are major physical and emotional changes associated with sexual development. Puberty is the physical change that prepares individuals to reproduce.
Puberty is the growth stage in which the reproductive organs mature. Girls begin puberty, on average, about two years before boys. For girls, physical changes associated with puberty usually begin between the ages of 10 and 14, but they may be seen as early as age 8. For boys, the normal age range for the start of puberty is between ages 12 and 16, but it can begin as early as age 9. The onset of puberty is not considered precocious unless it is before age 8 in girls or before age 9 in boys. African American girls, in general, start puberty a year earlier than girls of other races.
What starts puberty is unknown, but the hypothalamus, a small area located deep within the brain, plays a key role. During puberty the hypothalamus and pituitary gland, a pea-sized organ located just beneath the hypothalamus, send out chemical messages that cause the gonads, or sex glands (testes in boys, ovaries in girls), to increase production of sex hormones * (testosterone in boys; estrogen in girls). With the increase in these hormones, the body begins to develop secondary sex characteristics (such as body hair, breasts, a deeper voice) as well as to undergo a growth spurt.
The organs involved in sexual reproduction also enlarge and develop. For girls this series of changes leads to menstruation and signals that the body is capable of sexual reproduction (having babies). For boys these changes lead to the production of sperm. Boys may have experienced erections throughout childhood; however, ejaculation, the release of sperm in a fluid called semen, is only possible when this developmental level has been achieved.
Many studies suggest that neither girls nor boys are prepared for the physical changes that make their bodies seem strange and foreign. Most girls report they knew little or nothing about what usually is referred to as a “period” before their first menstrual flow. It is also typical for boys not to understand their newly acquired potential for ejaculation. Menstruation and ejaculation could be quite shocking and frightening experiences if one is unaware of them and unprepared.
The increase in growth rate that occurs during puberty is driven by the body's increase in the production of sex hormones: estrogen from the ovaries * in girls, and testosterone from the testicles * in boys. These hormones cause the skeleton to grow and to mature more rapidly. Hormones produced by the adrenal glands *
In general, puberty is considered precocious (early) if changes in sexual development occur before age eight for girls and before age nine for boys. Most cases of precocious puberty result from the premature switching on of the puberty control center in the brain, located in the part of the brain called the hypothalamus (hy-po-THAL-a-mus). Hormones from the hypothalamus trigger the release of hormones from the pituitary gland (located at the base of the brain), which in turn stimulate the ovaries in girls and the testicles in boys to produce the higher levels of sex hormones needed to bring about the bodily changes of puberty.
The early growth spurt associated with precocious puberty causes these children to grow taller than their peers initially. However, their skeletons mature more rapidly, causing them to stop growing at an age when their peers continue to grow. The result is that children with precocious puberty may end up smaller at the end of adolescence than their peers.
There are many possible causes for precocious puberty, including brain tumors * and other disorders of the central nervous system * , and tumors or other conditions that cause the gonads or adrenal glands to overproduce sex hormones. Childhood obesity * accelerates puberty and combined with other factors could lead to precocious puberty. In girls, the majority of cases of precocious puberty are idiopathic (id-ee-o-PATHik), which means the precise cause is unknown.
The first sign of puberty in girls is usually breast development and pubic hair. However, these signs of puberty may occur early without the gonadal changes that mark the true beginning of puberty. Therefore, early breast enlargement or pubic hair growth alone or together are not indicators of precocious puberty unless accompanied by gonadal changes.
Precocious puberty often can be treated effectively or controlled with medications that decrease the overproduction of sex hormones or that block their effects on the body. In many cases, this type of treatment can prevent or decrease the shortening of the child's ultimate height that would otherwise occur.
One of the main causes of delayed puberty is genetics * ; if one of the parents experienced delayed puberty, the child most likely will also experience delayed puberty. Also, female athletes, including gymnasts and ballerinas, often have delayed puberty. Several medical conditions (such as disorders of the hypothalamus, pituitary, ovaries, and testicles) can result in delayed puberty by interfering with the pubertal rise in sex hormones. Many chronic disorders of other body organs and systems (such as the intestines and lungs), as well as long-term treatments with certain medications (such as cortisone * ), also may cause delayed puberty.
Puberty is a normal developmental stage that involves rapid and dramatic changes. In addition to physical changes, adolescents also experience changes in mood, thinking, and social interests.
Changes in hormones in the adolescent body can trigger sudden and unpredictable changes in moods. One minute a boy or girl may be laughing and then, for no apparent reason, he or she can suddenly become angry or tearful. The different feelings that adolescents experience often make them feel like their emotions are on a roller coaster. The increased production of sex hormones is just one of many factors that contribute to these mood swings.
During this stage of life, adolescents develop the ability to think in more abstract and logical ways. They have a greater ability to examine their own, as well as other's, thoughts. These improved cognitive abilities often contribute to the disagreements between adults and adolescents as the adolescent is trying out new ways of thinking about various subjects. If adults are not prepared for the changing nature of the adolescent's thought process, then the adolescent may feel as if he or she is being misunderstood or treated like a child. Similarly, because adolescents are just beginning to develop these different cognitive abilities, there may be times when they want to think and act more like they did when they were younger. The adults around them need to respond to these changes and provide appropriate, challenging opportunities, but not opportunities that will overwhelm or frustrate the adolescent. The adults surrounding the adolescent are also learning about this changing, new person and are undergoing their own developmental process.
Adolescents have a new sense of personal uniqueness or egocentrism. At this stage, adolescents believe that no one else can ever understand how they feel, not parents, and not even friends. Sometimes, to maintain a sense of personal uniqueness, adolescents may have ideas and beliefs that seem inaccurate or unrealistic, which is a normal reaction to the changes that the adolescent is undergoing.
Sometimes adolescents believe they are indestructible or invulnerable to danger. This belief can lead to reckless behaviors such as drug use, fast driving, daredevil behaviors, suicidal thoughts, or sexual promiscuity. Adolescents may be unable to comprehend accurately the potential risks and negative outcomes of reckless acts. The difference between their perception of risk and adult understanding of it makes for generational conflict; adults are responsible for keeping adolescents safe, and adolescents perceive adult actions as overly controlling, cautious, or out of touch.
Adolescent development comes with many new and different physical and emotional feelings. Some of the most confusing may be the sexual thoughts that cause sensations or reactions in the body. Both girls and boys experience sexual feelings. These feelings are pleasurable and exciting and perfectly normal. Sometimes it is difficult to know what one is expected to do with these new sexual feelings. Adolescents are aware of many, often conflicting, beliefs about sex. For example, even though masturbation is a common characteristic of human sexuality, many people feel embarrassed to talk about it or may feel it is harmful or sinful. Adults can help adolescents learn that sexual development and the physical changes of their bodies are normal. Unfortunately, many adults are reluctant to discuss these subjects, and adolescents are left with the impression that there is something wrong or shameful about the natural functioning of their bodies.
Menstruation is a normal and important fact of a woman's life. Many young women are not adequately informed about menstruation. One study found that 43 percent of women felt frightened, panicky, or ill when they first started to menstruate. About one-third of women in another survey did not know about menstruation before they began menstruating. It is important for girls to be told about the various physical and emotional changes surrounding menstruation. For example, it is common for a woman's breasts to feel swollen and tender before her period begins. Other women experience temporary weight gain of a few pounds or sudden cravings for carbohydrates such as chocolate prior to their periods. Some women feel they are absent-minded or disorganized or that their emotions are out of control before their periods begin. Many women experience cramps (pains in the lower abdominal area) at the start of their periods. All of these symptoms are normal, and it is important that young women understand that these potential feelings are a natural part of menstruation.
When boys reach puberty they may begin to experience more frequent erections. Erections occur when blood rushes into the penis, causing it to swell and stiffen. Ejaculations occur when sperm mixes with fluids from the prostate gland and exits through the opening of the penis. It is through ejaculation that sperm leaves the male's body to enter the female's body when the two combine during sexual intercourse to begin a pregnancy. Not all erections lead to ejaculations or sexual intercourse. As boys mature, they may also have erections and orgasms during sleep. These are called nocturnal emissions (wet dreams). Nocturnal emissions are normal for boys. If a boy's pajamas or sheets are wet and sticky upon awakening, he has probably had a wet dream.
Sometimes a full bladder may cause an erection, so it is not uncommon for males to awaken with an erection. Because there are many ways to excite the penis to erection, sometimes men have erections for no apparent reason. Boys may have erections at inconvenient times that can be embarrassing, perplexing, or even anxiety provoking. While these experiences are embarrassing and troublesome, they are all quite normal.
While masturbation is a safe and available release for sexual tension, some people masturbate and some do not. It is a matter of personal choice, guided by personal beliefs and values.
While most people engage in some form of mutual sexual interaction at some time in their lives, when, with whom, and why are important factors that should be carefully considered before activities begin. In addition to the emotional price of having sex before one is ready, it poses some potential health risks and other problems. Unexpected pregnancy and sexually transmitted infections are two results that may occur after engaging in sexual intercourse.
Pregnancy is a natural outcome of sexual intercourse. Unless a couple is prepared and ready to start a family, an unexpected pregnancy can cause many problems. This is one of the major reasons why individuals should consider the consequences of acting on sexual desire before engaging in intercourse. There are many ways to prevent pregnancy. These methods are called contraception or birth control. The most effective method of contraception, and the only one that is 100 percent effective, is to refrain from all sexual intercourse until ready for pregnancy, which is called abstinence. Many religious groups and many parents support the idea that sexual intercourse should only occur in marriage. However, health educators are aware that sexual impulses and attraction are powerful urges, so education about contraception is part of the healthy sexuality curriculum in many public schools.
There are many methods of contraception. Using no protection against pregnancy by trying to time sexual contact or trying not to ejaculate * during intercourse are not effective. There are other methods of contraception that allow a couple to engage in sexual intercourse with different levels of protection against unwanted pregnancy. Men may use a condom, sometimes referred to as a rubber or jimmy, during intercourse. A condom is a soft, thin latex or polyurethane cover that fits over an erect penis.
Other forms of contraceptives include birth control pills, diaphragms, and intrauterine devices or IUDs. These methods are obtained from a doctor or health clinic. These methods are only used by women and require a thorough physical examination before they are prescribed.
Although the proper use of condoms can decrease the risk, abstaining from intercourse or other risky sexual activities is the only sure way to prevent the spread of sexually transmitted infections, such as HIV/AIDS, gonorrhea * , chlamydia * , and herpes * .
Sexual orientation refers to the pattern of one's feelings for and sexual attraction toward other people. People can be heterosexual, homosexual, or bisexual. Most people's orientation is heterosexual (attraction to the opposite sex). However, some people have homosexual (attraction to the same sex) or bisexual (attraction to both sexes) orientation, though not all of these people identify as gay. Less than 5 percent of Americans identified as gay (or lesbian) in surveys conducted in 2011, and less than 1.4 percent identified themselves as bisexual. There are many problems with obtaining reliable estimates of the numbers of gays, lesbians, and bisexuals in the population due to the homophobic discrimination these groups face.
During adolescence one's sexual orientation is often unsettled. Some people engage in various forms of sexual experimentation and exploration during early adolescence. Some experiment because an opportunity presents itself. Others do so out of curiosity or peer pressure. Still others are encouraged by their family to date before they are ready; this early dating may lead to sexual experimentation. These incidents of experimentation may not be consistent with a person's adult pattern of sexual orientation or attraction.
Sexual orientation is one fact of human sexual life, and it is central to everyone's core identity. Most people appear to be primarily heterosexual, so the causes for orientations that are not expressed by the majority are perplexing to many people. Many people wonder if homosexuality or bisexuality is a matter of choice. Are people born with their orientation already determined, or is orientation a matter of environmental factors? Many scientists believe in the early 21st century that sexual orientation is not a matter of choice. These scientists think sexual orientation is genetically determined, just like eye or skin color. Other scientists believe that childhood experiences contribute to determining sexual orientation. Many scientists feel that sexual orientation is determined by both genetics and life experiences. As of 2015, there was no conclusive scientific evidence that explained what determines sexual orientation.
See also Body Image • Lesbian, Gay, Bisexual, and Transgender (LGBT) Issues • Male Breast Enlargement • Menstruation and Menstrual Disorders • Pregnancy • Sexually Transmitted Infections (STIs): Overview
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* cognitive means associated with thinking, learning, perception, awareness, and judgment.
* hormones are chemical substances that are produced by various glands and sent into the bloodstream carrying messages that have certain effects on other parts of the body.
* ovaries (O-vuh-reez) are the sexual glands from which ova, or eggs, are released in women.
* testicles (TES-tih-kulz) are the paired male reproductive glands that produce sperm.
* adrenal glands (a-DREEN-al glands) are the pair of endocrine organs located near the kidneys.
* tumors (TOO-morz) are abnormal growths of body tissue that have no known cause or physiologic purpose. Tumors may or may not be cancerous.
* central nervous system (SEN-trul NER-vus SIS-tem) is the part of the nervous system that includes the brain and spinal cord.
* obesity (o-BEE-si-tee) is an excess of body fat. People are considered obese if they weigh more than 30 percent above what is healthy for their height.
* genetics (juh-NEH-tiks) is the branch of science that deals with heredity and the ways in which genes control the development and maintenance of organisms.
* cortisone (KOR-ti-zone) is a medication used to relieve inflammation.
* body image is a person's impressions, thoughts, feelings, and opinions about his or her body.
* ejaculate (e-JAH-kyoo-late) means to discharge semen from the penis.
* gonorrhea (gah-nuh-REE-uh) is a sexually transmitted disease (STD) spread through all forms of sexual intercourse. The bacteria can also be passed from an infected mother to her baby during childbirth. Gonorrhea can affect the genitals, urethra, rectum, eyes, throat, joints, and other tissues of the body.
* chlamydia (kla-MIH-dee-uh) are microorganisms that can infect the urinary tract, genitals, eyes, and respiratory tract, including the lungs.
* herpes (HER-peez) is a viral infection that can produce painful, recurring skin blisters around the mouth or the genitals, and sometimes symptoms of infection elsewhere in the body.