My niece (18) had the same thing and was very distressed about it. She went to her GP, was referred to a NHS specialist, and waited 6 mths for a breast enlargement for the small side. This was supposed to be done with an implant that has a port near the skin so that the size could be increased gradually over a few months while the skin stretched to match the other boob. Unfortunately the surgeon put the wrong size implant in, so it could not be increased. So the following year my friend had the large side reduced - now they match perfectly and she is so pleased with the results. And all on the NHS - fantastic - she is much more confident and happy now.