What is puberty and when does it start?

Written by: the Essense teamPublished: Medical review: pending. This article will be reviewed by a doctor before publication.

Puberty is the time when a child's body starts to change and mature. The World Health Organization defines adolescence, the wider stage of life, as ages 10 to 19, and calls it an important time for laying the foundations of good health[1].

When does it start?

There is no single "right" age. According to the NHS, puberty can start at any point between about 8 and 14, in both girls and boys[2]. Two children in the same class can be at very different points, and that is normal.

What changes does it bring?

On periods, the NHS says most girls start at around 12, but they can start as early as 8. It can also take some months for them to settle into a regular pattern[3].

When to talk to a doctor

The NHS advises a non-urgent appointment with a doctor if signs of puberty appear before 8, or haven't appeared by 15. It notes that usually there is nothing to worry about[4]. For periods, it advises seeing a doctor if they haven't started by 15[3]. In Greece, your first point of contact is your child's paediatrician.

How to talk about it

Talk early, before the changes start, so your child knows what to expect. Use the correct words for body parts. Show that every question is welcome. See how we cover this in the curriculum.

Sources

  1. World Health Organization. Adolescent health (health topic). www.who.int/health-topics/adolescent-health (opens in a new tab)
  2. NHS. Puberty (last reviewed 2 April 2026) (2026). www.nhs.uk/conditions/puberty/ (opens in a new tab)
  3. NHS. Starting periods (last reviewed 5 January 2023) (2023). www.nhs.uk/conditions/periods/starting-periods/ (opens in a new tab)
  4. NHS. Early or delayed puberty (last reviewed 2 April 2026) (2026). www.nhs.uk/conditions/early-or-delayed-puberty/ (opens in a new tab)