As you have noticed already, it is quite common for one breast to be somewhat larger than the other and this is not usually a sign of a medical problem. Sometimes, there can also be normal fluctuations in the size of the breasts, especially with the menstrual cycle, with pregnancy, or with lactation. However, it is also important to have any major change in the breasts, or in one breast, checked out by your doctor
, either your primary care doctor
or your OB GYN doctor.
This is because, occasionally, a change in the size of the breast may be a sign of a serious problem, such as a breast cancer. What your doctor will be able to do is perform a thorough examination of the breasts, looking for any evidence of a lump or mass within the breast, swollen glands in the armpit, or any other sign that might be concerning for cancer.
If any of these things are found, the next steps will be taking some pictures of the breast, such as with mammography
or with ultrasound. Based on what these pictures show, if a mass is identified, it might be necessary to perform a biopsy to rule out cancer.