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Puberty is the time during which sexual and physical characteristics mature. Precocious puberty is when these body changes happen earlier than normal.
Causes, incidence, and risk factors
Puberty usually begins between ages 10 and 14 for girls, and ages 12 and 16 for boys. Some African American girls may start puberty earlier, around age 9.
The exact age a child enters puberty depends on a number of factors, including family history, nutrition, and gender.
Often there is no clear cause for precocious puberty, but some cases are due to changes in the brain, genetic problems, or certain tumors that release hormones. These conditions include:
In girls, precocious puberty is when any of the following develop before age 8:
- Armpit or pubic hair
- Beginning to grow faster
- First period (menstruation)
- Mature outer genitals
Some evidence suggests that it may be normal for these changes to occur as early as age 7 in Caucasian girls and age 6 in African-American girls.
In boys, precocious puberty is when any of the following develop before age 9:
- Armpit or pubic hair
- Growth of the testes and penis
- Facial hair, often first on the upper lip
- Muscle growth
- Voice change (deepening)
Signs and tests
Blood hormone levels, CT scan of the brain or of the abdomen and MRI of the brain or of the abdomen are often used to diagnose the problem.
Medications can stop the release of sexual hormones. Some tumors need to be removed with surgery.
Children who go through puberty too early may not reach their full height because growth stops too early.
Children with early sexual development are more likely to have psychological and social problems. Children and adolescents generally want to be the same as their peers, and early sexual development can make them appear different. This can result in self-esteem problems, depression, acting out at school and home, and abuse of alcohol and illegal substances.
Calling your health care provider
See your health care provider if:
Styne DM, Grumbach MM. Puberty: Ontogeny, Neuroendocrinology, Physiology, and Disorders. In: Kronenberg HM, Melmed, S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier; 2008: chap 24.
- Last Reviewed on 08/02/2011
- Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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This page was last updated: May 31, 2013