and at the average age of 13 years for boys. A girl has reached 99% of her adult height at a bone age of 15 years and has a small amount of height growth left from this point on. A boy has reached 99% of his adult height at a bone age of 17 years and has a small amount of height growth left from this point on. When the bone age reaches 16 years in females and 18 years in males, growth in height is over, and they have reached their full adult height. There are exceptions with people who have an advanced bone age (bone age is older than chronological age) due to being an early bloomer (someone starting puberty and hitting PHV earlier than average), being an early bloomer with precocious puberty, or having another condition. There are also exceptions with people who have a delayed bone age (bone age is younger than chronological age) due to being a late bloomer (someone starting puberty and hitting PHV later than average), being a late bloomer with delayed puberty, or having another condition. An advanced or delayed bone age does not always indicate disease or "pathologic" growth. Conversely, bone age may be normal in some conditions of abnormal growth. Children do not mature at exactly the same time. Just as there is wide variation among the normal population in age of losing teeth or experiencing the first menstrual period, the bone age of a healthy child may be a year or two advanced or delayed. Those with an advanced bone age typically hit a growth spurt early on but stop growing at an earlier age. Consequently, when a naturally short child has an advanced bone age, it stunts their growth at an early age leaving them even shorter than they would have been. Because of this, those who are short with an advanced bone age, need medical attention before their bones fully fuse. An advanced bone age is common when a child has had prolonged elevation of sex steroid levels, as in precocious puberty or congenital adrenal hyperplasia. The bone age is often marginally advanced with premature adrenarche, when a child is overweight from a young age or when a child has lipodystrophy. Those with an advanced bone age typically hit a growth spurt early on but stop growing at an earlier age. Bone age may be significantly advanced