Gynaecomastia is a condition in which men develop abnormally large breasts. Some refer to this condition as "man boobs" or "moobs." When men develop large breasts it is due to an excess in the growth of the breast tissue and not due to excess fat tissue.
Gynaecomastia can occur in one or both breasts. Frequently, the breasts will enlarge disproportionately. This condition may emerge during puberty but generally goes away. However, sometimes it doesn't and an adult male ends up having big breasts.
Men have female hormones (oestrogen) just as women have male hormones (androgens.) When there are too many oestrogen in a man's body, or the body isn't using or responding to oestrogen correctly, this may result in enlarged breasts. The Mayo Clinic explains that gynaecomastia occurs when there is a decrease in testosterone levels compared with oestrogen levels. Testosterone is the hormone that controls male physical characteristics such as body hair and muscle mass, whereas oestrogen controls female traits, such as the growth of breasts.
Factors other than hormonally related issues that can result in enlarged breasts in men include kidney failure and dialysis; marijuana use; chemotherapy; use of anabolic steroids; hormone treatment for prostate cancer; chronic liver disease; medications such as cimetidine, metronidazole, ketoconazole and spironolactone; an overly active thyroid; tumours and genetic defects.
It's Up to You
Ultimately this is your choice, but wearing a bra can give you support and may make you feel more comfortable. It will also help conceal your breasts if that is your desire. According to Gynecoastiaguide.com, there are numerous products on the market for men with this condition. Some men opt for binding, which flattens their breasts, while others chose to layer their clothing to conceal their breasts. There is a "Frog Bra" or "The Bro," which is a sports bra and works well to support your breasts as well as conceal them. Some wear this bra or several bras at the same time underneath layered clothing to hide their breasts, although this sounds a bit cumbersome and not very comfortable.
Consider using an ace bandage, wrapping it around your breasts. This is an inexpensive method but not comfortable. Another suggestion is to cut off the legs of a pair of women's control top pantyhose and make a hole in the crotch area through which you will stick your head. Pull the pantyhose on over your head, slip your arms into the leg holes and you have devised a control top method for disguising your breasts.
Other possibilities include using a neoprene device around your chest because it will flatten it. The disadvantage is that this material, which is thick and rubbery, doesn't breathe, and you may chafe and blister as well as sweat while wearing it.