Overview

Precocious puberty is when children's bodies begin to change into adult bodies too soon. This change is known as puberty. Most of the time, puberty occurs after age 8 in girls and after age 9 in boys. However, Black, Hispanic, and Native American children might naturally reach puberty earlier. Precocious puberty is when puberty begins too early for the child who's going through it.

In puberty, muscles and bones grow quickly. Bodies change shape and size. And the body becomes able to have children.

The cause of precocious puberty often can't be found. Rarely, certain conditions, such as infections, hormone issues, tumors, brain issues or injuries, may cause precocious puberty. Treatment for precocious puberty usually includes medicines to delay puberty.

Symptoms

Precocious puberty symptoms include:

  • Breast growth and first period in girls.
  • Testicle and penis growth, facial hair and deeper voice in boys.
  • Pubic or underarm hair.
  • Rapid growth.
  • Acne.
  • Adult body odor.

When to see a doctor

Make an appointment with your child's health care provider if your child has symptoms of precocious puberty.

Causes

To understand the causes of precocious puberty in some children, it's helpful to know what happens at puberty. The brain starts the process by making a hormone called gonadotropin-releasing hormone (GnRH).

When this hormone reaches the small, bean-shaped gland at the base of the brain, called the pituitary gland, it leads to more estrogen in the ovaries and more testosterone in the testicles. Estrogen makes female sex traits. Testosterone makes male sex traits.

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

Central precocious puberty

The cause of this type of precocious puberty often isn't known.

With central precocious puberty, puberty starts too soon but develops as usual. For most children with this condition, there's no medical problem or other known reason for the early puberty.

In rare cases, the following can cause central precocious puberty:

  • A tumor in the brain or spinal cord.
  • A change in the brain that's present at birth. This could be fluid buildup, known as hydrocephalus, or a tumor that isn't cancer, known as a hamartoma.
  • Radiation to the brain or spinal cord.
  • Injury to the brain or spinal cord.
  • A rare genetic disease that affects bones and skin color and causes hormonal problems. This condition is called McCune-Albright syndrome.
  • A group of genetic issues, called congenital adrenal hyperplasia, that involve the adrenal gland making atypical hormones.
  • A condition called hypothyroidism in which the thyroid gland doesn't make enough hormones.

Peripheral precocious puberty

Estrogen or testosterone being made too soon causes this type of precocious puberty.

With this type of precocious puberty, the hormone in the brain (GnRH) that typically causes puberty to start isn't involved. Instead, the cause is the release of estrogen or testosterone into the body. A problem with the ovaries, testicles, adrenal glands or pituitary gland causes the hormone release.

The following can lead to peripheral precocious puberty:

  • A tumor in the adrenal glands or in the pituitary gland that releases estrogen or testosterone.
  • A rare genetic disease that affects bones and skin color and causes hormonal problems. This condition is called McCune-Albright syndrome.
  • Being exposed to creams or ointments that contain estrogen or testosterone.

In girls, peripheral precocious puberty also might be linked to:

  • Ovarian cysts.
  • Ovarian tumors.

In boys, peripheral precocious puberty also might be caused by:

  • A tumor in the cells that make sperm or in the cells that make testosterone.
  • A rare genetic condition called gonadotropin-independent familial sexual precocity. This can cause boys, usually between ages 1 and 4, to make testosterone too early.

Risk factors

Factors that increase the risk of precocious puberty include:

  • Being a girl. Girls are more likely than boys are to have precocious puberty.
  • Being obese. Carrying extra weight increases the risk of precocious puberty.

Complications

Possible complications of precocious puberty include:

  • Short height. Children with precocious puberty might grow quickly at first and be taller than others their ages. But their bones mature too soon. So these children often stop growing earlier than usual. This can cause them to be shorter than average as adults.
  • Social and emotional problems. Children who begin puberty long before others of their age might be upset about the changes in their bodies. For example, dealing with early periods can cause distress. This might affect self-esteem and raise the risk of depression or using illegal drugs or alcohol.

Prevention

No one can avoid some of the risk factors for precocious puberty, such as sex and race. But there are things that can lower children's chances of precocious puberty, including:

  • Keep anything that contains estrogen or testosterone away from children. These might include prescription medicines for adults or diet supplements.
  • Encourage children to stay at a healthy weight.
By Mayo Clinic Staff