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.

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.

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.

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.

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.

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.

Diagnosing precocious puberty involves:

• Reviewing the child's and the family's medical histories.
• Doing a physical exam.
• Running blood tests to measure hormone levels.

X-rays of children's hands and wrists also are helpful in diagnosing precocious puberty. These X-rays can show if the bones are growing too quickly.

Finding the type of precocious puberty

A test called a gonadotropin-releasing hormone (GnRH) stimulation test helps identify the type of precocious puberty.

The test involves taking a blood sample, then giving the child a shot containing the GnRH hormone. More blood samples taken over a period of time show how hormones in the child's body react.

In children with central precocious puberty, the GnRH hormone causes other hormone levels to rise. In children with peripheral precocious puberty, other hormone levels stay the same.

Other tests for central precocious puberty

• MRI of the brain. This imaging exam can show if children who have central precocious puberty have brain issues that are causing the early start of puberty.
• Thyroid testing. This test can show if the thyroid gland isn't making enough thyroid hormone — a condition called hypothyroidism. The test might be used with children who have symptoms of hypothyroidism, such as being tired, reacting to cold, starting to do poorly in school or having pale, dry skin.

Other tests for peripheral precocious puberty

Children with peripheral precocious puberty need more testing to find the cause of their condition. This might include more blood tests to check hormone levels or, in girls, an ultrasound to check for an ovarian cyst or tumor.

The primary goal of treatment is for children to grow to adult height.

Treatment for precocious puberty depends on the cause. However, when no cause can be found, treatment may not be needed, depending on the child's age and how fast puberty is moving. Watching the child for several months might be an option.

Treating central precocious puberty

This usually involves medicine called GnRH analogue therapy, which delays further development. It may be a monthly shot with medicine such as leuprolide acetate (Lupron Depot), or triptorelin (Trelstar, Triptodur Kit). Or some newer formulations can be given at longer intervals.

Children keep getting this medicine until they reach the usual age of puberty. After the treatment stops, puberty starts again.

Another treatment option for central precocious puberty is a histrelin implant, which lasts up to a year. This treatment doesn't involve monthly shots. But it does involve minor surgery to put the implant under the skin of the upper arm. After a year, the implant is removed. If needed, a new implant takes its place.

Treating an underlying medical condition

If another medical condition is causing precocious puberty, stopping puberty means treating that condition. For example, if a tumor makes hormones that cause precocious puberty, puberty usually stops after taking out the tumor.

Children who begin puberty early may feel unlike other children their age. There are few studies on the emotional effects of precocious puberty. But early puberty might lead to social and emotional problems. One result of that could be having sex at an early age.

Counseling can help families better understand and handle the feelings and issues that may come with precocious puberty. For answers to questions or for help finding a counselor, talk with a member of your child's health care team.

You're likely to start by seeing your child's primary care provider. Or you might be sent to a specialist in the treatment of hormone-related conditions in children, known as a pediatric endocrinologist.

Here's information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything your child needs to do beforehand, such as not eating for a few hours. Take a copy of your child's growth record if you're seeing a new health care provider who doesn't have your child's medical records.

Before the appointment, talk to your child about what to expect. Make sure your child understands that the appointment likely will include an exam of the genitals and breasts.

Make a list of:

• Your child's symptoms and when you noticed them. Include any that may not seem linked to the reason for the appointment.
• Key personal information, such as major stresses or recent life changes.
• All medicines, vitamins or other supplements your child takes, including doses. Write down what other people in the home take too.
• Make a list of family members' heights, noting if any of them are short as adults.
• Your family medical history, noting if any family members have had precocious puberty or endocrine problems.
• Questions to ask your child's doctor.

For precocious puberty, some questions to ask might include:

• What is likely causing my child's symptoms?
• Are there other possible causes?
• What tests does my child need?
• Is this condition likely to go away or will it be long term?
• What's the best treatment?
• When should treatment begin, and how long will it last?
• My child has other health conditions. How can we best manage them together?
• Is there anything my child can't eat or do?
• Do you have brochures I can take home? What websites do you recommend?

Be sure to ask all the questions you have.

What to expect from your doctor

Your health care provider is likely to ask you questions about:

• When puberty began for others in the family.
• Racial makeup of the family.