Breast asymmetry is found in the vast majority of women (more than 90%, by some estimates) to a more or less visible extent. Size differences can vary for any number of reasons. Depending on the extent of asymmetry, there may be medical issues, including increased breast cancer risk.
Frequency of occurence
More or less noticeable breast asymmetry is found in more than 90% of women, making it the rule rather than the exception. Asymmetry can manifest itself in the size of the breast, the position of the nipple and areola, the angle of the breast, and the position of the breast fold/root (where the breast meets the chest). The left breast is on average larger than the right (due to the left breast's proximity to the heart; protective tissue over the heart along with increased vascularity both project the breast outward and increase its growth).
Breast asymmetry may grow more or less pronounced, or even emerge at any point in an individual's life for a multitude of reasons, such as:
- menstrual cycle
- weight gain/loss
- ribcage asymmetry
- genetics/random growth patterns
- medical conditions (ex: virginal hypertrophy)
- previous surgical procedures
- ↑ 1.0 1.1 Panfilov, Dimitrije (2005). Cosmetic Surgery Today: "Breast Asymmetry"
- ↑ 2.0 2.1 Losken, A., et al.: "An objective evaluation of breast symmetry and shape differences using 3-dimensional images."
- ↑ 3.0 3.1 WdxCyber: "Breast Size Asymmetry"
- ↑ Jelovsek, Frederick. WdxCyber: "Breast Asymmetry - When Does It Need Treatment?"