Mine is the classic pubescent hormonal imbalance. It never went away. By the time I was in my mid 20's, I was a B cup in size. I became depressed about it and started putting on the weight. I was morbidly obese with a body index over 50 for many, many, many years. While it was easier to hide my chest with the excess weight, finally the excess weight began to cause health issues. High blood pressure, high cholesterol, joint issues, and others. My doctor told me either I lose the weight or a heart attack or stroke or diabetes were imminent. I couldn't continue to be like this. So I started on a diet and fitness program. I have so far lost close to 100 pounds and have toned up through a trainer. My BMI is now at 30. I have never felt better since I was a teenager. While I have lost some size in my breasts due to upper body work, being overweight for all those years, the estrogen created due to the fat increased the glandular tissue where my breasts are larger than before I put on weight even though I have lost so much weight. I recently was measured at a 38DD.
The upper body work has really improved my upper body look, the breasts are still there and will be without surgery but my overall appearance has improved to the point that with the properly sized and shaped shirt, (not a tent or over sized shirt) the effect is greatly reduced. At this point, I have just accepted my chest as is because I am beyond tired of worrying. It is what it is and I am now at the age that I am not intimidated by my body. I just got "sick and tired of being sick and tired" as the old saying goes. I realized that as long as I am as physically fit as can be, am doing what I need to be doing, have no medical issues due to my breasts, my body is normal for me. It is society with the hangup. Working with a trainer has certainly been a good thing and has really improved my body image, even with the noticeable breast tissue. While this is not the answer for everyone, it seems to be the answer for me, but working out the upper chest, no matter what breast size a person has, will help in better appearance, that is a big takeaway I never expected to have. Having a toned chest reduces the effect of having breasts.