Sexual Development



Normal sexual development follows a predictable yet individually variable course in children as they grow up and progress through puberty.  In general in boys puberty comes a bit later, and the linear growth or getting taller comes a little later in puberty than in girls.  The common names for the stages of sexual development are called the Tanner stages, and progress from Tanner Stage 1 through Tanner Stage 5 for both males and females.  First let’s look at an overview of development for boys and girls, then outline the Tanner stages for boys and the Tanner stages for girls. The Tanner stages are a great way to have a better understanding of sex education.

Girls first sign of puberty is usually breast bud development.  This happens at any age from 8 until about 13 and is called telarche.  In 40% of girls pubic hair growth may precede telarche. This is followed by further breast tissue development and pubic and axillary hair growth.  The growth spurt in height usually occurs around the time between telarche and the onset of menses.  The onset of menses follows telarche by 1 ½ – 3 years in most girls.  Further breast growth continues, and puberty and growth are usually complete by 1-2 years after the first menstrual period.

Boys first sign of puberty is usually starting to develop pubic and axillary hair growth.  This is followed by gradual growth in the size of the testes and penis, and by change in their voice.  Further growth in genital size continues and facial hair growth starts to varying degrees for different individuals.  The spurt in linear growth or height usually is in this mid to late puberty for most boys.  Over the next couple of years genital growth reaches adult form, and linear growth gradually slows and stops, at varying rates for different individual boys.

Both boys and girls tend to have a “fat spurt” or become a bit pudgy during the pre-puberty to early puberty time frame, and they tend to slim down again as the growth in height progresses.

Here is a table of the characteristics of both boys and girls by their Tanner Sexual Development Stage:

Girls Boys
Tanner Stage 1 prepubescent Prepubescent
Tanner Stage 2 Small amount of long soft hair on labia majora, breast buds form and areola begin to widen, growth spurt may begin as early as this time. Small amount of long fine hair at base of scrotum and penis, testes grow slightly,
Tanner Stage 3 Pubic hair begins to become more curly and thick and spread in location, breast begins to grow in elevation and outside the areola, but areola remains at the same contour as the rest of the breast.  Menarche can vary from Tanner 1 or 2, typically Tanner 3-4. Pubic hair begins to become more curly and thick and spread in location, testes continue to grow and penis starts to lengthen to about 6 cm. Some boys begin linear growth, others later in Tanner Stage 4.
Tanner Stage 4 Pubic hair becomes adult quality and covers the pubis, breasts continue to grow and the areola tends to form a secondary mound  that projects in contour from the rest of the breast. Pubic hair becomes adult quality and covers the pubis, testes and penis continue to grow, penis length typically about 10 cm.
Tanner Stage 5 Pubic hair extends to the inner thighs, breasts reach adult size and the areola contour tends to return to the contour of the rest of the breast with the central nipple protruding. Pubic hair extends to the inner thighs, the testes and penis reach adult sizes.

Common normal issues noted during puberty include:

Gynecomastia:  breast tissue development in boys occurs during puberty in up to 70% of boys, and can be one sided or occur on both sides.  This is rarely significant and usually resolves without treatment.  In severe cases surgery may be done to remove the breast tissue.

Acne:  This is very common in adolescence, and if it is more than minor to moderate you should seek help from your family physician, pediatrician, or dermatologist.  Excellent treatment options are available, and very few children are so difficult to treat that significant scarring cannot be avoided.

Irregular menstrual periods:  Most girls have irregular timing and duration of their menses for the first few months and up to the first 2 years of their menstrual cycles.  This is of no concern unless the bleeding is very heavy and excess blood loss is suspected.  If bleeding goes on longer than 2 weeks, or if a girl needs to change pads or tampons more than every 1-2 hours for over a day or two she should be evaluated by her primary care physician.

Menstrual Cramps:  Mild to moderate menstrual cramps are usually normal, and can be treated with ibuprofen or naproxen.  If this is not adequate to prevent missing school or normal activities, or if the pain is severe despite these treatments, a girl should discuss this with her physician.  Effective treatment is usually possible, and sometimes evaluation for endometriosis is needed.

Emotional Changes prior to or during the menstrual cycle are common, typically called premenstrual syndrome, or PMS.  This can be mild moodiness, or quite severe.  Headaches, constipation, pelvic pressure, and abdominal bloating can accompany PMS, and if these symptoms are interfering with normal activities, or if they are severe enough to affect a young woman’s relationships with family or friends she should consult with her primary care physician or gynecologist.