Posted by William on May 14, 2012
Your 14-year-old son has always been healthy. Last fall’s jacket is now too short, and you notice his voice is lower too. But he’s a head shorter than his best friend of the same age, and he’s wondering when he’s going to get tall. What can you and he expect?
The first sign that puberty is beginning for a boy is an enlargement of the testes and scrotum. Testes enlargement marks the increased production of testosterone and other male hormones (androgens) that bring about the other dramatic changes of male adolescence.
During elementary school, the average boy grows about 2 to 2.5 inches each year. In the year or two before puberty begins, height growth slows down a bit.
The average boy’s height growth spurt begins at age 12, usually about two years after girls begin their pubertal height increase. However, some boys may start growing as early as age 9 or 10, or as late as 14 or 15. The growth spurt lasts about four years.
A boy’s peak rate of growth usually happens at 13 or 14, but it can occur anywhere between ages 11 and 15. At his peak rate a boy is growing as much as 3.5 to 4.5 inches per year. No wonder he is constantly in the refrigerator! Boys generally reach their adult height by age 17 or 18, but we’ve all known young men who continued growing during the college years.
Testosterone also stimulates muscular development in the growing boy, as well as the bone growth that results in increased height. The adolescent weight spurt in the boy occurs at about the same time as the height spurt.
Your son will gain 12 to 25 pounds a year (on average, about 20 pounds a year) during the height spurt. A good deal of that weight is muscle and bone. A boy’s weight increases from about 85 pounds at the beginning of puberty to an adult weight of 150 pounds or more by age 18.
Androgens are also responsible for other changes in the genitals of boys. The penis grows in length and then later in width, usually about a year before the boy reaches his peak growth rate. The developing testes produce sperm and semen relatively early in adolescence. The boy’s first ejaculation of sperm usually occurs at age 13 or 14, often in the form of a “wet dream” or during masturbation.
Pubic and underarm hair develops soon after genital growth, along with the maturation of skin glands. Sweat glands produce “adult” sweat with odor, and oil glands on the face can become clogged with oily material and develop into acne, especially around age 15 or 16. Boys may be disturbed about the acne but reluctant to request help in managing it. New medications can be a big help.
Facial hair usually appears about age 15, first on the upper lip, then later on the chin and in the sideburn area. In general, chest and other body hair do not develop until late adolescence or early adulthood.
Testosterone increases the size of the boy’s larynx (voice box), which becomes more visible as the “Adam’s apple.” The thickening of the vocal cords results in the lowering of the adolescent’s speaking and singing voice — sometimes rather unexpectedly!
All those inches and pounds of growth are associated with an increase in the size of the brain, liver and other organs, and an increase in the number of red blood cells — all of which mean the boy needs a diet rich in protein, calcium, iron and other nutrients for optimal growth.
A boy’s appetite is nothing short of phenomenal during these adolescent years, and it’s sometimes hard to keep enough milk in the house! Growth alone will require about 3,000 calories a day for the boy, not counting the increased calories he’ll need for soccer, basketball, track or other sports.
The weekly food bill for a family with adolescent boys is impressive!
Your boy’s growth pattern or tempo may not be the same as his friends’ — he may grow “too soon” or “too late” in his mind. Compared with girls, adolescent boys are less likely to have visits with their pediatrician. Your son’s doctor can make the most of school sports and camp physical visits by assessing his growth and reassuring him about normality as well as giving other good-sense adolescent advice.