Breast development is usually one of the first signs of female puberty. It can occur between the ages of 8 and 13 for girls and is the result of increased estrogen levels. Breast development usually continues throughout the teen years, and can vary from person to person. There are several breast growth patterns that can occur during this time frame, many of which may seem abnormal and which can cause distress to a teen and her family.
As many as 2 percent of girls will develop an extra nipple or breast, according to the MassGeneral Hospital for Children. This abnormal breast development is most likely to occur during a teen pregnancy, and the extra nipple is usually located along the milk line from the armpit to the thigh. Girls may elect to remove the extra breast tissue surgically, although doctors usually recommend that this occur after puberty and growth are complete.
Absence of Breast Development
When a teen girl does not have breast tissue by the age of 13, her breast development is considered delayed, according to Brookside Associates. The Dallas-based Plastic and Craniofacial Surgery for Infants and Children website notes that although rare, the breast bud may be nonexistent due to a chest wall deformity or failure of the underlying pectoralis muscle to develop properly. Girls with chronic illnesses like Crohn’s disease, Turner syndrome or an eating disorder may also fail to grow buds by the age of 13.
Excessively Large Breasts
The development of extremely large breasts can cause a teen girl not only emotional distress but also physical distress. According to the Plastic and Craniofacial Surgery for Infants and Children, excessively large breasts can cause pain to the back, neck, shoulder, and head, and even cause hand and finger numbness. MassGeneral Hospital for Children notes that in some cases large breasts can cause the upper spine to curve forward--a condition known as kyphosis. Doctors sometimes recommend breast reduction for kyphosis cases after breasts are fully mature.
Up to 25 percent of teens will have breasts growing in an asymmetrical fashion, according to MassGeneral Hospital for Children, and many women reach full maturity with one breast that is larger than the other. While parents or teens who are concerned should seek a medical evaluation, padded bras can often provide camouflage.
Breast Development in Teen Boys
Some boys may also experience breast development during their teen years, although the Plastic and Craniofacial Surgery for Infants and Children website notes that this usually resolves itself within two years. It is important to note that some substance abuse, including marijuana use, can aggravate the condition. It is not uncommon for teen boys with this abnormality to become self-conscious. Although breast growth in boys is often hereditary, parents should seek medical attention to look for any hormonal or endocrine imbalance.