Puberty is the period of adolescence during which a child undergoes rapid physical, hormonal and psychological changes and gradually develops into a sexually mature individual. One of the important changes during puberty is the development of secondary sexual characteristics. These are physical features that distinguish males and females after puberty but are not directly involved in the reproductive process. Their development is mainly controlled by hormones released from the testes in boys and ovaries in girls, under the regulation of the pituitary gland and hypothalamus. In boys, puberty generally begins between 9 and 14 years, although the timing varies among individuals. The testes begin producing increased amounts of testosterone, which brings about several changes in the body. One of the earliest noticeable changes is the enlargement of the testes and scrotum, followed by growth of the penis. The reproductive organs themselves are primary sexual characteristics, while changes such as body hair, voice and muscular development are secondary characteristics. A major secondary sexual characteristic in boys is the growth of hair. Hair appears in the pubic region and under the arms and later becomes thicker on the face, chest and other parts of the body. The voice also