Premature puberty or precocious puberty is an uncommon condition wherein the physical changes brought about by puberty begins earlier than usual, that is, before the age of 8 for girls and before age 9 for boys.

For the initial diagnosis of premature puberty, the review of the child's medical history, a physical examination, and blood tests (to measure hormone levels), may be done. After which, the doctor will determine the type of premature puberty that afflicts the child, by performing a test that involves injection of the GnRH hormone and then taking a blood sample. MRI of the brain, usually of those with central premature puberty, is performed.

In the treatment for premature puberty, the cause must be considered. Medication and GnRH analogue therapy, which stops the HPG axis, and delays further development, are treatment options. If it is caused by an underlying medical condition, the said cause must be treated.

Premature puberty in girls exhibits the following symptoms: breast growth and early menstruation before the age of eight. Boys experiencing premature puberty, on the other hand, have enlarged testicles and penis, deepening voice, and facial hair, before the age of 9. The symptoms common to both boys and girls are rapid growth, acne, pubic or underarm hair, adult body odor.

The main cause of central precocious puberty is that the entire HPG axis starts too soon. The other causes of central precocious puberty may include a tumor in the central nervous system, a congenital defect in the brain, injury to the brain or spinal cord. On the other hand, peripheral precocious puberty is caused by the release of estrogen or testosterone into the body because of problems with the ovaries, testicles, adrenal, or pituitary glands. A tumor in the adrenal glands or in the pituitary gland and exposure to external sources of estrogen or testosterone may likewise lead to premature puberty in both boys and girls.