The first sign of puberty (at around 10 years) in boys is usually that their testicles get bigger and the scrotum begins to thin and redden and pubic hair also starts to appear at the base of the penis.

After approximately one year, further changes occur:

• underarm hair starts to grow
• boys start to sweat more (this can also lead to body odour)
• breasts can swell slightly temporarily
• boys may have “wet dreams” (involuntary ejaculations during sleep)
• their voice “breaks” and gets permanently deeper. Sudden changes in pitch are normal while this is happening.
• boys often develop acne – a skin condition that shows up as different types of spots, including whiteheads, blackheads and pus-filled spots called pustules
• boys go through a growth spurt and become taller by an average of 7 to 8cms a year, and their bosy shape changes as they become more muscular