Precocious puberty, or early onset puberty, means a boy or girl has started to mature sexually too early. In general, it refers to girls who start to develop sexual characteristics before age 8 and boys who begin this process before age 9.

Precocious puberty is rare. It affects about 1 in 5,000 to 10,000 children.

Read on to learn how to identify this condition and what to do if you suspect your child is experiencing early onset puberty.

For boys and girls, precocious puberty leads to abnormally early growth of bones and muscles. The body starts the kind of changes that usually first develop when a child is closer to their teenage years.

Signs of precocious puberty in both boys and girls include:

  • a rapid growth spurt
  • development of pubic and underarm hair
  • acne
  • adult body odor

Signs in girls

For girls, other precocious puberty symptoms include:

  • start of menstruation
  • breast development

Signs in boys

For boys, the other signs of precocious puberty are:

  • enlarged testicles and penis
  • growth of facial hair
  • spontaneous erections and ejaculations
  • a deepening voice

There are two main types of this condition: central precocious puberty and peripheral precocious puberty.

Their causes differ, but the changes they trigger in the body are similar.

Central precocious puberty

Central precocious puberty (CPP) occurs when the brain secretes gonadotropins at an abnormally young age.

Gonadotropins are hormones released by the pituitary gland. They signal the gonads, located in girls’ ovaries and boys’ testicles, to produce sex hormones responsible for the physical changes associated with puberty.

It’s often not clear what causes central precocious puberty. Most children with this condition have no other serious medical problems or underlying health concerns that could trigger early onset puberty.

In some cases, though, central precocious puberty may be associated with:

  • brain or spinal tumor
  • injury to the brain or spinal cord
  • fluid buildup in the brain at birth
  • hypothyroidism, an underactive thyroid gland

Peripheral precocious puberty

Peripheral precocious puberty (PPP) is less common than CPP. Unlike CPP, PPP isn’t stimulated by the pituitary gland’s premature release of gonadotropins.

Instead, it results from the early production of the hormones androgen and estrogen in other parts of the body. This is why it’s sometimes referred to as gonadotropin independent precocious puberty (GIPP).

The early production of androgen and estrogen may be caused by underlying problems with the:

  • testicles
  • ovaries
  • adrenal glands
  • pituitary gland

Some possible causes include:

  • tumors in the pituitary or adrenal glands
  • ovarian cysts in girls
  • testicular tumors in boys
  • McCune-Albright syndrome, an uncommon genetic disorder that can cause problems with hormone production, skin color, and bone health

Other forms of precocious puberty

Two less-serious types of precocious puberty can also develop.

One is called premature thelarche, which causes mild breast development in girls. The development is limited and can eventually disappear until normal puberty occurs.

The other form of precocious puberty is premature adrenarche. It occurs when the adrenal glands secrete androgen at an especially young age. The result is a small amount of pubic hair growth and the start of adult body odor. However, no other features of puberty develop until the expected age-range for puberty.

Treatment for these two types of precocious puberty is not necessary.

Precocious puberty affects girls at a much higher rate than boys. African-American children also face higher risks of this rare condition.

Your child may be at increased risk for precocious puberty if there’s a family history of the condition.

Researchers are learning more about genetic risk factors, such as a mutation of the kisspeptin gene (KISS1) and its receptor (KISS1R). A gene passed down on the father’s side, MKRN3, may also play a role in early onset puberty.

Other risk factors for precocious puberty include:

  • obesity
  • ingestion or exposure to products containing testosterone or estrogen, such as birth control pills, or hormone creams and ointments
  • radiation treatment of the brain or spinal cord for tumors, leukemia, and similar conditions

Children affected by precocious puberty will usually be taller than their peers at first. However, because their growth plates will seal at a younger age, they’ll often be shorter than average in adulthood.

Children may also become self-conscious and feel awkward about the changes they’re going through. Complications such as low self-esteem, depression, and substance misuse can occur later on.

Counseling may be helpful.

Consult your pediatrician at the first signs of puberty in a child younger than 8 or 9. Even if you’re unsure if what you’re seeing is a sign of puberty, take your child to the doctor for an evaluation.

Your pediatrician will review your child’s medical history and family medical history. A physical exam will also be necessary.

Your doctor may also recommend an X-ray to help determine the “age” of your child’s bones. Indications that the bones are growing faster than normal can help confirm or rule out the diagnosis.

A gonadotropin-releasing hormone (Gn-RH) stimulation test and a blood test to check for levels of other hormones, such as testosterone in boys and progesterone in girls, can help confirm a diagnosis of precocious puberty.

In children with central precocious puberty, Gn-RH will cause other hormone levels to increase. Hormone levels will remain the same in children with peripheral precocious puberty.

A painless, non-invasive magnetic resonance imaging (MRI) scan may also help reveal problems with the pituitary gland.

Your child may not need treatment if their precocious puberty is mild or is progressing slowly. They also may not need treatment if the condition develops closer to the age of puberty.

Otherwise, treatment will depend on the type of precocious puberty affecting your child.

Central precocious puberty

The goal of CPP treatment is to pause the pituitary gland’s production of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).

A medication called a GnRH agonist can help block the gland’s gonadal activity. It’s usually given as an injection every one to three months, or as an implant that slowly releases the medication over the course of a year.

In addition to slowing puberty, this treatment may allow a child to grow taller than they would have without any treatment.

After 16 months or so, the treatment usually stops and puberty resumes.

Peripheral precocious puberty

Because PPP usually stems from an underlying cause, such as a tumor, treating the underlying condition (such as removing the tumor) may be enough to stop the early onset of puberty.

However, medications to stop the premature production of estrogen and testosterone may also be prescribed.

Much of the risk of precocious puberty is associated with gender, race, and family history, as well as other causes that are largely unavoidable, so you’re limited in what you can do to prevent this condition.

Keeping your child’s weight in a healthy range may help lower their risk of precocious puberty and other conditions associated with obesity and being overweight, such as type 2 diabetes.

You should also avoid giving your child prescription hormone medications, dietary supplements, or other products that may contain estrogen or testosterone, unless prescribed or recommended by their doctor.

Your child may have a lot of questions about what’s happening with their body. Classmates can say things that are hurtful, perhaps even unintentionally.

It’s important to take the time to listen to your child’s concerns and answer questions sensitively, but honestly.

Explain that everyone goes through puberty at a different time. Some kids start early and some kids start much later. Emphasize, though, that all these body changes will happen to everybody at some point.

Keep in mind that early onset puberty sometimes leads to early sexual feelings. Be understanding of your child’s curiosity and confusion about the changes brought on by the premature production of sex-related hormones.

But set clear boundaries about behaviors, and keep an open dialogue about values, priorities, and healthy choices.

Treat your child as normally as possible, looking for opportunities to boost self-esteem. Encouraging participation in sports, the arts, and other activities, along with recognizing success in the classroom, can help with self-confidence.

Don’t hesitate to take your child to a counselor to learn coping strategies. Your child may be more comfortable talking about some personal things with a therapist, rather than a parent, at least in the beginning.

A children’s hospital that treats kids with precocious puberty may have counselors experienced in helping children with this specific condition.

Precocious puberty usually doesn’t lead to any long-term health problems. Being shorter than average may be the extent of the effects that linger into adulthood.

With proper treatment and counseling, if necessary, children with precocious puberty can often have a happy and healthy adolescence and adulthood.