Tanner stages

Tanner stages or Tanner scale is a scale of physical development in children, adolescents and adults. The scale defines physical measurements of development based on external primary and secondary sexual characteristics, such as the size of the breasts, genitals, testicular volume and development of pubic hair. This scale was first described by James Tanner, a British pediatrician, and thus, it is named after him.

Overview

The Tanner stages are used by pediatricians, endocrinologists, and other medical professionals to monitor the development of children and adolescents. They are a central part of adolescent medicine and are included in the diagnostic criteria for numerous medical conditions associated with puberty and development.

Stages

The Tanner stages consist of five stages for male and female physical development. Each stage describes a different level of physical development.

Male Tanner stages

• Stage I: Prepubertal; no sexual development is apparent.
• Stage II: The testicles and scrotum begin to enlarge; there is little or no pubic hair.
• Stage III: The penis begins to grow in length; the testicles continue to grow; pubic hair becomes darker and coarser.
• Stage IV: The penis and glans develop further; the testicles continue to grow; pubic hair is adult-like but not yet spread to the inner thighs.
• Stage V: Genitalia are of adult size and shape; pubic hair has spread to the inner thighs.

Female Tanner stages

• Stage I: Prepubertal; no sexual development is apparent.
• Stage II: The breasts bud and the areola enlarges; there is little or no pubic hair.
• Stage III: The breasts and areola continue to enlarge; pubic hair becomes darker and coarser.
• Stage IV: The areola and papilla form a secondary mound above the level of the breasts; pubic hair is adult-like but not yet spread to the inner thighs.
• Stage V: Breasts are of adult size and shape; pubic hair has spread to the inner thighs.

Clinical significance

The Tanner stages are used in pediatric and adolescent medicine to assess and monitor a child's development. They can help identify any developmental delays or early onset of puberty. The stages are also used in endocrinology studies and research, and in diagnosing and treating conditions such as precocious puberty and delayed puberty.

See also

• Puberty
• Adolescent medicine
• Endocrinology
• James Tanner