Precocious puberty in girls is the premature onset of puberty, beginning before the age of 8 years. It is rare and affects only about 1 child in every 10,000 in the United States. Premature stimulation of the endocrine system releases hormones from the pituitary gland at the base of the brain. These hormones stimulate the ovaries to make sex hormones. The sex hormones, including estrogen, cause sexual maturation in girls.
Sex hormones accelerate growth and also control the skeletal process that ends growth.
Girls who start puberty prematurely are tall for their age, but growth stops earlier for them. Their full height potential as adults is never achieved. They often grow no taller than 5 feet. Behavioral changes during premature puberty include moodiness and irritability similar to that seen in teenage girls. They may become too self-conscious with their physical changes to undress in front of others, including parents.