Precocious puberty

Alternative names
Pubertas praecox


Precocious puberty is premature development of body characteristics that normally occur during puberty. (Puberty is the period in life when the body changes rapidly and develops reproductive capability). Puberty normally occurs between 13 and 15 years old in boys, and between 9 and 16 years old in girls.

In girls, precocious puberty is when any of the following develop before 8 years of age:

  • Breasts  
  • Armpit or pubic hair  
  • Mature external genitalia  
  • First menstruation

Some evidence suggests that it may be normal if these changes occur as early as 7 years in Caucasian girls and 6 years in African American girls.

In boys, precocious puberty is when any of the following develop before 9 years of age:

  • Enlarged testes and penis  
  • Armpit or pubic hair  
  • Facial hair, usually first noted on the upper lip

Causes, incidence, and risk factors

The main causes are structural abnormalities in the brain and hormone-secreting tumors.

Signs and tests

Blood hormone levels, computerized brain scans, and abdominal scans are often used to diagnose the problem.


Medications can temporarily surpress sexual hormone secretion. Some tumors require surgical removal.


Children of both sexes with early sexual development are more likely to have psycho-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 alcohol and illegal substance abuse.

Calling your health care provider

See your health care provider if:

  • Your child shows signs of precocious puberty  
  • Any child with early sexual development appears to be having social problems in school

Johns Hopkins patient information

Last revised: December 5, 2012
by Potos A. Aagen, M.D.

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