When should I worry if one breast is bigger than the other?

It is normal for women to have one breast bigger than the other. Most women have uneven breasts–or they have different shapes.

Sometimes, a woman will notice that one breast increases significantly in size from her baseline. This should always be evaluated with physical examination and imaging, especially if the change happens over a short period of time (days to weeks). Solid masses, fluid collections and infections are common causes of sudden breast enlargement.

Trinity Health is a Catholic health care organization that acts in accordance with the Catholic tradition and does not condone or support all practices covered in this site. In case of emergency call 911. This site is educational and not a substitute for professional medical advice, always seek the advice of a qualified healthcare provider.

Having breasts of two different sizes is common. In this video, I will discuss when asymmetric breasts should be worried about.

It is quite common for each breast to be slightly different in size, a condition called asymmetry. Breast asymmetry is defined as a difference of form, position or volume of the breast, and it affects more than half of all women. In fact, one study of 100 women who wanted breast augmentation with implants found that 88 percent had natural asymmetries.