"I am a 52 yr old fit male who 2 years ago had a normal male chest. Medications causing a hormonal imbalance have resulted in me growing fully "female" breasts, not fat sacks. I had a professional bra fitting & found out im a 38 C, and since I do not have extra body fat, they clearly stand out as "female" breasts. I wanted to clarify that not just fat guys can get boobs."
This may sound odd if you've never thought about it, but some straight men do wear bras (they are not transsexual, cross-dressers, or wanting to have breasts). Men may in some cases feel compelled to wear a bra if they have considerable amount of breast tissue and feel the need to hide that fact.
For these men the bra just is a garment as any other; it is not anything sexual. (Of course it doesn't have to be a sexual garment for women either.) It is also possible to find special vests (gynecomastia vests) for this purpose.
All men have breasts and nipples but usually there is so little of the actual breast tissue that they appear flat-chested. However, there are many reasons why men or boys might have visible or protruding breasts. The medical term for this is gynecomastia.
"I am 49 years old. Six years ago I was diagnosed with testicular cancer. After two years of chemo, surgery was performed. In addition, I was put on reverse HRT. Since that time my breast have begun to grow nonstop. I am now a 42C and must wear a sports bra everyday to suppress additional movement. ...my doctor expects my growth to reach a 42D by this time next year. I don't have a problem with having large breast for they are a part of me. Plus, I will be here to see the arrival of my third grandson this September."
One reason is a hormonal imbalance during puberty. In fact, this can happen up to 40% of teenage boys. This condition will disappear in 90% of these boys within 3 years or less.
Other reasons are side effects of some prescription drugs, or some diseases of the hormonal system of the body (hormonal imbalances). For example, testicular cancer often results in growth of the breast tissue. And there are yet other reasons. If a man's testosterone production drops considerably, his breasts can develop, because all men do produce some estrogen (which drives the breast growth).
Note that if a man has visible breast growth, that does not mean he is homosexual, though many people seem to think so, and men who suffer from gynecomastica are often ridiculed as being "gays". Conversely, a homosexual person does not necessarily have breast growth.
Growing breasts is of course usually very embarrassing for the boy or man, but it may help to know that you are not alone. Even if you wear bras to hide your breasts, you are not alone.
You will find more information and support forums and groups by searching the internet with the medical term 'gynecomastia' in your search; for example searching for 'gynecomastia forum' in major search engines yields good results.
Remember also the special garment "gynecomastia vest" designed for men with the problem.
Gynecomastia in Teens