Males

• first sign is testicular growth at around 12 years of age (range = 10-15 years)
• testicular volume > 4 ml indicates onset of puberty
• maximum height spurt at 14

Females

• first sign is breast development at around 11.5 years of age (range = 9-13 years)
• height spurt reaches its maximum early in puberty (at 12) , before menarche
• menarche at 13 (11-15)
• there is an increase of only about 4% of height following menarche

Normal changes in puberty

• gynaecomastia may develop in boys
• asymmetrical breast growth may occur in girls
• diffuse enlargement of the thyroid gland may be seen