Why does delayed puberty occur?

Many reasons: Delayed pubertal development can be caused by many things. A child can merely be a late bloomer, he or she can have an underlying chronic illness that delays pubertal development, there can be a defect in production of pubertal hormones or a resistance to these hormones or there can be an underlying genetic disorder that is associated with pubertal delay. This is not a comprehensive list however.

Puberty: Normal puberty starts anywhere from 9 to 16 years. The start is influenced by a number of factors including weight, environmental, genetic, and structural.The growth spurt, breast development and pubic hair growth all usually start before the menses. A pediatrician should be able to help with a simple exam and possible some blood tests or ultrasounds.