What Are the Tanner Stages?
Medically reviewed by Jonathan B. Jassey, DO
Tanner staging, also known as sexual maturity rating (SMR), is a tool healthcare providers use to track development during puberty. It outlines five specific stages for the physical changes during this period, including genital, breast, and pubic hair development.
This article discusses the Tanner stages tool, outlining its use and providing context into potential issues it can help flag.
Tanner Staging Defined
The Tanner staging scale defines physical development milestones based on specific sex characteristics. This includes the size of the genitals, breasts, and testicles, and pubic hair growth.
Puberty is the period when a child starts to become sexually mature. For people assigned female at birth, these physical changes typically happen between ages 10 and 14. For people born male, the changes usually occur between ages 12 and 16.
What Are the 5 Tanner Stages?
Healthcare providers use the Tanner stages to document and describe the physical changes people undergo during puberty. Each person will travel through the Tanner stages at different rates, but this puberty timeline helps record physical milestones to ensure development is on track.
Rated on a 5-point scale, males are assessed for genital development and pubic hair growth, while girls are assessed for breast and pubic hair growth.
Tanner Stage 1
Pubic hair: In females, this preadolescent stage is characterized by fine, short hair like peach fuzz called vellus hair developing over the genital area. In males, the same type of peach fuzz will appear around the genitals and close to the abdomen.
Breasts: Breasts appear during childhood, with the nipple slightly elevated above the chest.
Male genitalia: The testicles, scrotum, and penis are similar in size as they were during childhood.
Tanner Stage 2
Pubic hair: During this stage, more pigmented, but mostly straight, hair appears around the genital area. This is considered to be an initial appearance of actual pubic hair.
Breasts: The breasts and nipple start to elevate more, appearing as small mounds or buds.
Male genitalia: The scrotum and testicles start to get larger, and there may be a change in the texture of the skin in that area.
Tanner Stage 3
Pubic hair: At this point, darker, coarser, and curlier hair starts to develop on the genital area of both sexes. In addition, the amount of hair increases and spreads more noticeably across the genital region.
Breasts: The breasts and nipple continue to get bigger but haven't started to fill out or take the shape of more developed breasts yet.
Male genitalia: The penis gets longer and a bit wider, and the testicles and scrotum also see some growth.
Tanner Stage 4
Pubic hair: Pubic hair distribution in this stage is closer to what it would look like in an adult but may be more sparse and not quite reaching the thigh area.
Breasts: The nipple begins to elevate above the breast mound, and breast tissue develops.
Male genitalia: At this point, the penis is significantly bigger in length and width. The testicles and scrotum also enlarge, and the skin in that area gets darker.
Tanner Stage 5
Pubic hair: Pubic hair is now completely developed as it will be in adulthood, in shape, hair density, and distribution (known as terminal hair).
Breasts: Matured female breasts are fully developed at this point.
Male genitalia: The penis is now fully formed as it will be in adulthood, including shape and size.
What Is Tanner Staging Used For?
Tanner staging is used in pediatric (child) and adolescent (preteen) medical settings. Healthcare providers utilize it to keep track of patients' body changes during puberty, help counsel patients about the puberty timeline, recommend appropriate medical screenings, and monitor for any potentially related issues.
A healthcare provider might use Tanner staging to give a patient guidance in advance on what to expect when their menstrual cycle starts or to give context into when a related medical screening will need to take place, such as a scoliosis exam.
What Are the Advantages?
Experts have pointed out that the Tanner staging tool is helpful for accurately gauging the sexual maturity rating for adolescent patients. It is not physically invasive and allows for some adjustment based on each person's time frame for starting and ending the puberty stage.
What Is the Medical Significance?
Puberty is a part of normal human growth and development. This period in your life involves relatively rapid growth and numerous physical—along with emotional—changes. If puberty isn't happening around the average time frame, getting additional medical care for this issue might be necessary.
By using Tanner staging, healthcare providers can be made aware of any developmental changes that may be considered abnormal. The Tanner staging tool allows this to happen aligned and uniformly so that providers across the board use the same criteria to gauge their adolescent patients' health.
What's Considered Average/Healthy?
It's important to point out that everyone develops differently and at a different rate during puberty. While this period typically lasts roughly two to three years, each person's experience during puberty will vary slightly.
Tanner staging helps flag whether development is happening at an average or healthy rate. This allows healthcare providers to watch for abnormal (but treatable) signs of issues such as:
Precocious puberty: Defined as developing breast buds or fine pubic hair before age 8
Delayed puberty: May look like there is no breast development by age 13
Primary amenorrhea: A failure to start your menstrual cycle by age 15 if you've already had normal breast and pubic hair development
Summary
Healthcare providers use Tanner staging to assess the status and progression of physical changes during puberty, the time when a child's body transitions into adulthood. The Tanner stages consist of five milestones for the various physical markers of puberty.
This tool allows healthcare providers to gauge whether puberty development is happening on track and recommend appropriate medical care if it isn't.
