Normal timing
- Girls: breast development usually starts between 8 and 13, with periods about 2 to 3 years later
- Boys: enlargement of the testes usually starts between 9 and 14
What counts as early
Breast development before 8 in girls, or testicular enlargement before 9 in boys, is called precocious puberty. In girls, no underlying cause is found in most cases. In boys, an underlying cause is more often present, so assessment is especially important.
Signs that are often harmless
Breast buds alone in a toddler, or body odour and a little pubic hair without other changes, are often benign. They still deserve a check to make sure they are not progressing.
Why it matters
- Bones may mature early, so final adult height can be shorter
- Early periods and body changes can be hard for a young child emotionally
What assessment involves
- Height, growth rate and stage of puberty
- A hand X-ray for bone age
- Blood tests for puberty hormones, sometimes with a stimulation test
- A pelvic ultrasound in girls, and a brain MRI when advised
Treatment
When puberty is truly early and progressing, monthly or three-monthly injections can pause it until a more suitable age. Any underlying cause is treated.
When to see a specialist
Seek an assessment if your child shows signs before these ages, if changes are progressing quickly, or if your child is growing much faster than before.
This guide is general information and is not a substitute for a consultation.
Related guides
Endocrine care for children at the clinic All patient guides