Originally Published: September 22, 2000 - Last Updated / Reviewed On: December 23, 2008
This has been bothering me for a while, but I'm too embarrassed to mention it to anyone. Is it common to have breasts that are different sizes? There's almost a cup size difference between my breasts. I'm almost eighteen, and I don't know if they'll "even out" as I get older, or not, or if this is something to worry about.
This is not something to worry about. Few women have identical breasts. The difference between each breast, or even nipple, can be slight, or more obvious, especially after puberty. Breast size and shape are unique for each woman. Some breasts do not fill an A cup while others exceed a DD; one breast may be firm while the other sags; some are smooth under the skin and others are more lumpy.
As you get older, it's possible that your breasts may become more "even" in size. Throughout a woman's lifetime, breast size and shape change in response to fluctuation in hormone levels. While menstruating, breasts become fuller and more tender; when pregnant and nursing, they generally enlarge a great deal; and, during menopause, breasts may become more lumpy. Taking hormonal contraceptives (see Does taking the pill increase the size of your breasts?) or gaining or losing weight (check out Breast implants) also alters the size of the breast. Knowing that your breasts will go through normal changes may make you feel more comfortable.
Since there are many individual differences in breast size and shape, it is important to know what is "normal" for you. Becoming familiar with your breasts will help you to notice any changes in your breast tissue that may be a cause for concern. If you detect anything different from the usual, see your health care provider. This is why regularly examining your breasts is important.
To learn more about Breast Self-Exams (BSEs), see Breast lump in Alice's Sexual Health archive. To receive a free BSE reminder card with BSE instructions that hangs in your shower, contact the American Cancer Society at 800.227.2345 and request the Breast Self-Exam Shower Card.