The Tanner Stages, also known as the Tanner scale or Sexual Maturity Rating (SMR), are a standardized system used by healthcare professionals to assess and track the progression of physical development in children and adolescents during puberty. This scale offers a consistent framework for monitoring typical pubertal changes and identifying any significant deviations that might warrant medical attention.
The Tanner Scale Explained
The Tanner Scale is structured into five distinct stages, from Stage 1 to Stage 5, representing a continuum of development. For females, the scale primarily evaluates two key areas of physical change: breast development and pubic hair growth. Stage 1 on the scale signifies a pre-pubertal state, meaning no outward physical signs of puberty are yet visible. Conversely, Stage 5 indicates that full adult physical development has been achieved in the assessed characteristics. Each subsequent stage outlines specific, observable changes that mark progression through puberty.
Breast Development Stages
Female breast development, often termed thelarche, is categorized into five Tanner stages.
Stage B1
This pre-pubertal phase shows only the papilla, or nipple, elevated. There is no palpable glandular breast tissue.
Stage B2
Breast budding begins with the elevation of the breast and papilla as a small mound. The areola, the pigmented area around the nipple, may also enlarge.
Stage B3
Further enlargement of the breast and areola occurs, although their contours remain continuous without a clear separation.
Stage B4
The areola and papilla elevate above the breast, forming a distinct secondary mound.
Stage B5
Mature breast development is reached. The breast has achieved its adult contour, and the areola has receded to the general contour of the breast, with only the papilla protruding.
Pubic Hair Development Stages
Pubic hair development in females also progresses through five Tanner stages.
Stage PH1
This stage is characterized by the absence of pubic hair, with only fine vellus hair present, similar to the hair found on the abdomen.
Stage PH2
Sparse, long, slightly pigmented, and often straight or only slightly curled hair appears, primarily along the labia. This initial growth marks the beginning of pubic hair development, also known as pubarche.
Stage PH3
The pubic hair becomes noticeably darker, coarser, and curlier, spreading sparsely over the junction of the pubes.
Stage PH4
Hair distribution becomes adult in type, with coarser, darker, and curlier hair, but the area covered is smaller, not yet extending to the medial surface of the thighs.
Stage PH5
Full adult pubic hair development is reached, with adult quantity and type of hair, forming an inverse triangle pattern and spreading to the medial surface of the thighs.
Expected Ages and Puberty Timing
The timing of pubertal development in females exhibits considerable variability, though general age ranges are associated with each Tanner stage. Breast budding, marking the onset of puberty (Tanner Stage B2), typically begins around 8 to 13 years of age, with an average onset at approximately 10 years for White Americans and 8.9 years for African Americans. Pubic hair development (Tanner Stage PH2) usually follows breast budding by about 1 to 1.5 years, often appearing around 11.2 years of age.
Progression to Tanner Stage B3 and PH3, where breast and pubic hair continue to enlarge and darken, respectively, often occurs around 11.9 years. By Tanner Stage B4, typically around 12.9 years, breasts form a secondary mound, and pubic hair becomes adult-like in quality, though not yet fully spread. Menarche, the onset of menstrual periods, commonly occurs between the ages of 12 and 14, generally about 2 to 2.5 years after breast budding begins. Full adult development, Tanner Stage 5, is often reached around 15 years of age for breasts and pubic hair, though some individuals may continue to develop until 18 years. It is important to remember that these ages are averages, and a wide range of normal variation exists in when puberty starts and how quickly it progresses for each individual.