The male body produces and increase in the hormone testosterone which kick starts the process of puberty. Sexual development in boys can start anywhere between the ages of 10 and 18 but usually happens around 13 or 14.
Physical changes in boys include:
Testicles becoming fuller and larger
Scrotum sac becomes darker in colour
Penis grows longer and wider
Testicles start to produce sperm which mixes with fluid to make semen which boys ejaculate
Spontaneous erections and wet dreams begin
Growth of facial hair and hair on arms and legs which becomes darker and thicker
Growth spurt including arms, legs and feet
Voice box grows, making Adam’s apple look bigger, and voice breaks and becomes deeper
Pubic hair grows around base of penis
Sweating more, greasier hair and skin and possible spots or acne
Body shape changes as shoulders become broader and chest becomes more muscular
