Adolescence: The period of life starting with the appearance of secondary sex characteristics and ending with the ceasing of the body's overall growth.
Bone age: The stage of development of the skeleton as compared with x-ray views of bone structures of other individuals who are the same age.
Central precocious puberty (CPP): A condition in which the physical and hormonal signs of puberty develop in children at an earlier age than is considered normal. CPP is caused by the early release of hormones by the brain.
Chronological age: A person's actual age in terms of years and months.
CPP: See central precocious puberty.
Estrogen: Female sex hormone responsible for the development of secondary sex characteristics and involved in the reproductive cycle in women.
Follicle-stimulating hormone (FSH): A hormone released by the pituitary gland that stimulates the ovaries to produce estrogen and the testicles to produce testosterone—which lead to the changes you see during puberty.
FSH: See follicle-stimulating hormone.
GnRH: See gonadotropin-releasing hormone.
Gonadotropin-releasing hormone (GnRH): A hormone made by the hypothalamus (part of the brain) that causes the pituitary gland (a small gland at the base of the brain) to release two other hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
Gonadotropin-releasing hormone (GnRH) agonist: The most common treatment for CPP. GnRH agonists work by making sure the pituitary gland stops sending hormones to stimulate the ovaries and testes to produce sex hormones.
Hormone: A chemical substance produced in an organ of the body (like the adrenal glands or the pituitary gland) and carried to another organ or tissue in the body, where it has a specific effect.
Hypothalamus: A part of the brain that regulates a number of basic body functions, like temperature, sleep, food intake, and the development of secondary sex characteristics.
LH: See luteinizing hormone.
Luteinizing hormone (LH): A hormone released by the pituitary gland that stimulates the ovaries to produce estrogen and the testicles to produce testosterone—which lead to the changes you see during puberty.
Pediatric endocrinologist: A doctor who specializes in the treatment of hormone-related conditions in children.
Pituitary gland: A small gland located at the base of the brain that helps control the release of hormones.
Precocious: Maturity that is unusually early for a person of that age; showing premature development.
Puberty: The period when a person begins to develop secondary sex characteristics and becomes capable of sexual reproduction.
Tanner Stage: A stage of puberty as set out on the Tanner growth chart, based on the growth of pubic hair in both sexes, the development of the genitalia in boys, and the development of the breasts in girls.
Testosterone: Male sex hormone (a small amount is produced by females as well) that is responsible for producing masculine secondary sex characteristics such as growth of body hair and the development of the male reproductive system.