Puberty is the stage in human development during which a child's body matures into an adult body capable of sexual reproduction. This process is triggered and controlled by hormones — chemical messengers secreted by endocrine glands. It usually begins between ages 9–14 for girls and 11–16 for boys, though it can vary slightly from person to person.

What Triggers Puberty?

Puberty is initiated by signals from the brain, specifically the hypothalamus. It stimulates the pituitary gland to release hormones that act on the reproductive organs.

• Hypothalamus: Releases gonadotropin-releasing hormone (GnRH)
• Pituitary Gland: In response to GnRH, releases:
  • Luteinizing Hormone (LH)
  • Follicle-Stimulating Hormone (FSH)
• Testes (in males): Produce testosterone
• Ovaries (in females): Produce estrogen and progesterone

Hormonal Changes in Males

In boys, puberty typically begins between ages 9–14. The key hormone is testosterone, which causes:

• Growth of facial and body hair
• Deepening of the voice
• Increased muscle mass
• Growth of testes and penis
• Production of sperm

Hormonal Changes in Females

In girls, puberty usually begins between ages 8–13. The main hormones are estrogen and progesterone, which lead to:

• Development of breasts
• Start of menstruation (menarche)
• Widening of hips
• Growth of pubic and underarm hair
• Maturation of ovaries and uterus

Other Common Changes During Puberty (Both Genders)

• Growth spurts (increase in height and weight)
• Increased oil and sweat gland activity → acne, body odor
• Emotional changes and mood swings
• Development of sexual feelings and attraction

Why Are Hormones Important?

Hormones coordinate complex processes like physical growth, sexual maturation, and emotional development. They ensure that all parts of the body change at the right time and in the right sequence.

Summary Table

Gland	Hormone	Main Function
Hypothalamus	GnRH	Stimulates pituitary gland
Pituitary	LH & FSH	Stimulate testes/ovaries
Testes	Testosterone	Male sexual development
Ovaries	Estrogen, Progesterone	Female sexual development

Written by: Thenura Wickramaratna