Symptoms:

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

• Armpit or pubic hair
• Beginning to grow faster
• Breasts
• 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.