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When Should Puberty Start?

Question of the Week


Updated March 26, 2005

Q. My daughter is 9 years old and is beginning to 'develop'. Is it normal for children to start puberty so young?

A. Yes. In general, 9 is a very appropriate age for your child to start puberty.

Puberty normally occurs in a series of five stages (Tanner stages) that typically begin within the ages of 8 and 13 for girls and 9 and 14 for boys. Puberty is consider early (precocious) if it occurs before the age of 8 years in girls and 9 years in boys. And puberty is considered late or delayed if it has not begun prior to the age of 13 years for girls and 14 years for boys. Recent studies have shown that puberty is occurring at an increasingly earlier age in children though.

The first sign of puberty in girls, which occurs at an average age of 10 1/2 years, is breast development (thelarche). This begins with breast budding, or the formation of small lumps or nodules under one or both nipples. These lumps may be tender and they may be different sizes at first. This is usually also the beginning of their growth spurt. Next, in about six months, pubic hair develops (adrenarche), although in some children, pubic hair is the first sign of puberty, and then axillary hair begins to grow. Over the next few years, breast size will continue to increase and there will be a progressive increase in development of pubic hair and the external genitalia, leading to the first period or menarche (occurring at an average age of 12 1/2 to 13 years), which usually occurs about two years after puberty begins and coincides with their peak in height velocity. Development continues and the whole process is completed in 3-4 years, eventually reaching adult breast and areolar size and an adult pattern of pubic hair. A child will have also reached her final adult height about two years after menarche.

Puberty generally begins later in boys, at an average age of 11 1/2 to 12 years. The first sign of puberty in boys is an increase in size of the testicles. This is followed a few months later by the growth of pubic hair. Puberty continues with an increase in size of the testicles and penis and continued growth of pubic and axillary hair. Boys undergo their peak growth spurt about 2-3 years later than girls. Also, this usually begins with an enlargement of the hands and feet and is later followed by growth in the arms, legs, trunk and chest. Other changes include a deepening of the voice, an increase in muscle mass, the ability to get erections and ejaculate (especially spontaneous nocturnal emissions or 'wet dreams'), and in some boys, breast development (gynecomastia). Development continues and the whole process is completed in 3-4 years, eventually reaching adult testicle and penis size and an adult pattern of pubic hair. This is followed by the development of chest and facial hair. Puberty is also associated with adolescents beginning to have axillary perspiration and body odor, and acne.

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