Puberty

Puberty starts when extra amounts of chemicals called hormones start to be produced in the body. These hormones guide the changes that take place in the body. As well as causing physical changes these hormones also cause emotional changes to occur.

The table below summarizes the physical events at each stage of development. The changes associated with puberty generally occur gradually between the ages of 9 and 16 years. The age of puberty can vary considerably from person to person.

Stages of Development of Puberty

Age Years (these will vary)	Features	What happens (Boys)	What happens (Girls)
9 - 16	Menstruation		Menstrual cycle, or "period," begins. Most girls get their periods between 9 and 16 years of age. During puberty, the ovaries begin to release eggs. If an egg is fertilized by sperm from a man's penis, it will grow inside the uterus and develop into a baby. To prepare for this, a thick layer of tissue and blood cells builds up in the uterus. If the egg does not meet with a sperm, these tissues and cells are not needed by the body. They turn into a blood-like fluid and flow out of the vagina.
10 - 17	Growth Spurt and the Body shape	While both girls and boys will begin a rapid growth spurt sometime between the ages of 10 and 15, the growth spurt in boys usually occurs about two years after the growth spurt takes place in girls of the same age. Boys will get taller and will gain a lot of weight. Muscles will also get bigger. The body takes on a more muscular and angular shape under the influence of testosterone. The greatest effect can usually be seen in the upper chest and shoulder muscles. Testosterone also causes bones to lengthen, giving young men a heavier bone structure and longer arms and legs. During this time, many boys also experience swelling under their nipples. Do not worry. It is a temporary condition.	Body shape: Hips get wider and your waist will get smaller. The body will also begin to build up fat in the stomach, buttocks, and legs. This is normal and gives your body the curvier shape of a woman. Body size: Arms, legs, hands, and feet may grow faster than the rest of your body. Until the rest of the body catches up, girls may feel a little clumsier than usual.
11 - 14	Growth of hair and pubic hair	Hair usually begins to grow on various parts of the body when a boy is between ages 11 and 14 years. Hair is typically seen on a young man's face, underarm area, pubic area (area in the lower abdomen between the legs), abdomen, chest, arms, legs, and buttocks. The amount and distribution of hair can vary considerably from one man to the next -- this is entirely normal and may have genetic tendencies.	Soft hair will start to grow in the pubic area. This hair will eventually become thick and very curly. Girls may also notice hair under their arms and on their legs.
11 - 15	Voice changes	As a result of increased testosterone (male hormone), vocal cords become longer and thicker. The voice will get deeper. This may start with voice cracking which can often be very embarrassing. As boys continue to grow, the cracking will stop and the voice will stay at the lower range.
11 - 15	Breast		In most girls, puberty starts with breast growth under the influence of Estrogen, (female hormone). The pigmented area around the nipple, called areola, enlarges and becomes darker. It raises to become a mound with a small amount of breast tissue underneath. This is called a bud. These small, tender lumps under one or both nipples will get bigger over the next few years. When breasts first begin to develop, it is not unusual for one breast to be larger than the other. However, as they develop, they will most likely even out before they reach their final size and shape.
11 - 20	Pimples (Acne)	Skin may get oilier and the teenager may notice he/she sweat more. This is because glands are growing too. It is important to wash every day to keep the skin clean and to use a deodorant or antiperspirant to keep odor and wetness under control. Despite best efforts to keep the face clean, one still may get pimples. This is called acne and is normal during this time when hormone levels are high. Almost all teenagers get acne at one time or another. Whether the case is mild or severe, there are things one can do to keep it under control.
13 - 16	External Genital Development	Penis and testes will get larger. Increased growth of the penis and scrotum often starts at about age 13 and continues until adult size is reached about 2 years later. There is a fair degree of variation in the age for genital development from one boy to the next. The skin of scrotum gets thicker and pigmented around the age of 12. Boys may have erections more often due to an increase in male hormones. Erections occur when the penis gets stiff and hard - sometimes for no reason. This is normal. Even though you may feel embarrassed, try to remember that most people will not even notice your erection unless you draw attention to it. Many boys become concerned about their penis size; a boy may compare his own penis size with that of his friends. It is important to remember that the size of a man's penis has nothing to do with his manliness or sexual functioning. During puberty the body will also begin to produce sperm. This means that during an erection, you may also experience ejaculation. This occurs when semen (made up of sperm and other fluids) is released through the penis. This could happen while sleeping. You might wake up to find your sheets or pajamas are wet. This is called a nocturnal emission or "wet dream." This is normal and will stop as you get older.	The skin around the genitals get pigmented and the lips of the vulva (labia minora and labia majora) become bigger.