Precocious ("early") puberty is caused by chemicals in the body (hormones) that get sexual development started sooner than expected. Precocious puberty can happen to both girls and boys. It is not all that common.

Everyone arrives at puberty at different times. Girls under the age of seven or eight and boys under the age of nine who show early signs of puberty should be checked by a doctor.

Some early signs of puberty can be:

• Growth of testicles for boys or breast buds for girls
• Pubic or underarm hair growth
• A growth spurt (rapid increase in height)
• Skin with acne or pimples

It is a good sign that your son's hormone tests were normal. Plus, his bone age is within one year of his actual age, which may also be fine.

Most importantly, your son should continue to be checked by his pediatrician.

Precocious puberty can lead to early growth that ends too soon, so the child does not reach her or his full height. When a child’s growth appears to be slowing sooner than expected, he or she may need to see a pediatric specialist called an endocrinologist. This doctor is an expert in the hormones and glands of the body.

We usually do not find a specific cause for precocious puberty in girls, but we might in boys. Most girls (about 90%) who experience precocious puberty are otherwise healthy. They develop early but normally, and no specific treatment is usually necessary.

In contrast, only about half of the boys who experience precocious puberty are otherwise healthy. This means that about 10% of girls and 50% of boys who develop early signs of puberty may have other health concerns. These can sometimes be serious, like an abnormal growth in the brain or in the neck (thyroid gland). Treatment is determined by the type of underlying medical problem.

Puberty is a period of rapid change that can be scary -- or at least awkward. Parents and pediatricians can make sure every child enters adolescence in good physical and emotional health.