The appropriate size of breast implants is determined by a number of factors including: a patient's expectations, her anatomy and physical health, her weight, and other considerations. A good plastic surgeon will discourage a patient from extreme breast enlargement if s/he believes that the possible risks outweigh the intended benefits of the procedure. Many women do not have enough breast tissue to cover and/or support extreme breast enlargement, which can lead to a variety of health problems.

If a patient does not have the chest structure to support extreme breast enlargement, she could suffer a host of different medical complications. If there is not enough glandular or muscular tissue to cover extreme breast enlargement implants, the edges of the implant can be palpable and visible after the operation. Patients may also experience unacceptable wrinkling, puckering, and dimpling due to extreme breast enlargement.

With extreme breast enlargement the effects of gravity are also exacerbated and the implants can shift or sag much sooner that smaller implants would. This means that a patient who has undergone extreme breast enlargement surgery will have to seek subsequent surgical procedures in order to have the implants removed or replaced. Extreme breast enhancement surgery also causes the natural breast tissues to greatly expand, meaning that when implants are removed (which will eventually be necessary) the breasts will be droopier and saggier than before the extreme breast enlargement surgery. Women who undergo extreme breast enlargement surgery also have a greater risk of suffering from back pain, shoulder problems, and other problems associated with large breasts.