Uneven breasts: Cosmetic problem or health concern?

There are many causes of asymmetric, or uneven, breasts. In many women, having slightly different-shaped or -sized breasts is normal. Occasionally, the size difference can be marked.

If you've always had asymmetric breasts you probably don't have to worry about it. However, if your breasts are normally close in size and you notice they are becoming asymmetrical, it is important to have this checked by your doctor. In some cases, new breast asymmetry can be a sign of an underlying condition that requires further evaluation.

Causes of uneven breasts include:

• Normal anatomic variations
• Hormone changes in puberty — for example, one breast may start developing before the other
• Fibrocystic breast changes
• Pregnancy
• Breast-feeding
• Hyperplasia, or excessive growth of normal tissue — such as pseudoangiomatous stromal hyperplasia
• Noncancerous breast cysts
• Noncancerous breast tumors, such as fibroadenomas, hamartomas and phyllodes tumors
• Breast cancer

If necessary, your doctor may recommend further testing to determine the cause of asymmetric, or uneven, breasts, including a mammogram, breast ultrasound or breast biopsy. There is no evidence that breast asymmetry is an individual risk factor for breast cancer. However, it is important for women to know what is "normal" for their breast appearance and to report any changes to their doctors.

In most cases, uneven breasts are simply a cosmetic concern. If the size difference bothers you, you can try foam inserts that fit into your bra or bathing suit. You may also consider plastic surgery.