Puberty usually starts between 8 and 13 years in girls and between 9 and 14 years in boys. Starting later than friends can be hard for a teenager. Most late starters are healthy and simply on a slower timetable, but delayed puberty can also signal a hormone problem that is easy to treat once found.
When puberty is considered delayed
- Girls: no breast development by age 13, or no periods by age 15 (or within 3 years of breast development starting)
- Boys: no enlargement of the testes by age 14. In boys, testicular growth is the first sign of puberty, before body hair or voice change.
- Either sex: puberty that starts and then stops progressing
Common causes
Constitutional delay of growth and puberty is the most common cause, especially in boys. These children are healthy but grow and mature later than average, and often one parent was also a late bloomer. They usually catch up fully in height and development.
Other causes include:
- Chronic illness or poor nutrition: celiac disease, anaemia, kidney disease, inflammatory bowel disease, or very low body weight
- Intense exercise or eating disorders, particularly in girls
- Hormone problems: underactive thyroid, high prolactin, or pituitary disorders
- Hypogonadotropic hypogonadism: the brain doesn't send the signal to start puberty (see male hormone problems). When combined with a poor or absent sense of smell, this is called Kallmann syndrome.
- Problems with the ovaries or testes: Turner syndrome in girls, Klinefelter syndrome in boys, or damage after chemotherapy, radiation or infection
Warning signs that need early review
- No sense of smell
- Very short stature, or growth that has slowed sharply
- Headaches, vision problems or milky discharge from the nipples
- Undescended testes or a very small penis in boys
- Puberty that started and then stalled
- Weight loss, tummy problems or a chronic illness
Tests
- A physical examination, including pubertal staging, done respectfully and with a parent present
- A bone age X-ray of the hand
- Blood tests: LH, FSH, testosterone or estradiol, thyroid function, prolactin, and general health tests
- Chromosome testing (karyotype) when Turner or Klinefelter syndrome is suspected
- An MRI of the pituitary in selected cases
Treatment
For healthy late bloomers, watchful waiting with regular measurements is often enough. If the delay is causing distress, a short, low-dose course of testosterone (for boys) or estrogen (for girls) can start puberty and is safe under supervision. When the cause is permanent, long-term hormone replacement brings on puberty and protects bone strength, and fertility options can be discussed later.
A note for parents
Teenagers who look younger than their friends may be teased, avoid sports, or quietly worry that something is wrong with them. Even when no treatment is needed, an assessment and a clear explanation often brings relief. Please don't use body-building supplements or "hormone tonics", which can be harmful.
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Written by Dr. Prasadh Rao L, MBBS, MD (General Medicine), DM (Endocrinology). Assistant Professor of Endocrinology, Madras Medical College. Tamil Nadu Medical Council Reg. No. 96520.
This article is for general information. It is not a diagnosis or a treatment plan. Please don't start, stop or change any medicine without speaking to your doctor.