Tanner stages

The Tanner stages (also known as the Tanner scale) are stages of physical development in children, adolescents and adults. The stages define physical measurements of development based on external primary and secondary sex characteristics, such as the size of the breasts, genitalia, and development of pubic hair.

Due to natural variation, individuals pass through the Tanner stages at different rates, depending in particular on the timing of puberty.

In HIV treatment, Tanner staging is used to determine which treatment regimen to follow (adult, adolescent, or pediatric).

The Tanner stages were first identified by (and named for) James Mourilyan Tanner.