At what Tanner stage does male testes and scrotum begin to enlarge?

The Tanner stages describe the physical development during puberty, and they encompass changes in primary and secondary sexual characteristics. In males, the first significant change noted in Tanner Stage 2 is the enlargement of the testes and scrotum. This stage signifies the onset of puberty and is characterized by hormonal changes that stimulate testicular growth and the beginning of spermatogenesis.

During Tanner Stage 1, which represents prepubertal development, there is no noticeable change in the size of the testes or scrotum. Tanner Stage 3 marks further development, including increased penis size and pubic hair growth, while Stage 4 involves considerable development but does not specifically pertain to the initial enlargement of the testes and scrotum. Therefore, Tanner Stage 2 is recognized as the stage when males first experience the enlargement of the testes and scrotum, indicating the onset of puberty.