Can One Breast Stop Developing While the Other Continues to Grow?

There are a number of options for creating a breast shape in a situation where one doesn't develop, but the key is to use some of the same techniques as with breast reconstruction. One option that I have found very useful is an expander-implant called Spectrum, made by Mentor. It is a saline implant that can be expanded slowly over a period of months to stretch out the skin enveope and fine-tune the volume. These procedures may not be covered by insurance but there is a grant program through the American Society for Aesthetic Plastic Surgery (surgery.org) that can help in situations like yours if finances are an obstacle.

Thank you for your question.  Some degree of breast asymmetry is in fact far more common than perfectly symmetrical breasts.  Your size difference may truly be a normal variant.  Bearing that in mind, there are certain developmental conditions (Poland's syndrome, for example) in which one breast fails to develop completely.  There is unlikely any non-surgical option which will correct your problem.  One-sided breast augmentation (or both-sided, with different size implants), plus or minus tissue expansion of the smaller side (depending on the degree of underdevelopment) will be the best option to give you a result with which you'll be happy.

The vast majority of women have some degree of breast asymmetry. This asymmetry occurs for a variety of reasons. It can be related to the volume of the breasts, or in some cases, to the shape of the breasts. In some cases, asymmetry may be related to the position of the nipple areola complexes, while in other cases, it may be related to deformities of the underlying chest-wall.Regardless of the cause, a cup size difference isn't an unusual finding. When this problem is encountered, a variety of surgical options are available to treat this problem. If you're concerned about breast asymmetry, it's important to consult a board certified plastic surgeon. This surgeon should be able to formulate a treatment plan that addresses your concerns.

Thank you for your question. If you are looking to decrease the asymmetry from one breast to another, then you have several options.
1) You can reduce the larger breast with liposuction
2) You can enlarge the smaller one with fat grafting or an implant
3) You can enlarge both but use different size implants
I would visit with a board certified plastic surgeon to discuss your options in more detail.  Non-surgical options are not effective in addressing developmental asymmetry.

Asymmetry is definitely the norm for women. One breast is always different in shape or size than the other. The only problem is when the asymmetry is very apparent, which could cause embarrassment for the woman affected. You can get breast augmentation or a reduction surgery to balance out your breasts, but there is no non-invasive treatment that's either FDA approved or safe. 

In general, female breasts stop developing at around 18 or 19 years old. How old are you? This is when a primary level of maturity is achieved, however further changes occur with pregnancy and lactation (the production of breast milk). Your breasts will continue to change throughout your life, as the signs of aging become more apparent. For example, your breasts may begin to droop as supportive tissues weaken, or grow larger when you gain weight. Please note that nobody's breasts are symmetrical. Every woman has one breast that may be different in shape and/or size, and this asymmetry varies. It can be mild to severe, but note that this is totally normal. The only treatment that is safe and effective is cosmetic breast surgery.