Men wear bras because they either enjoy dressing in women's lingerie or because they struggle with a condition called gynecomastia, which causes the breast tissue of men to swell and resemble the appearance of female breasts. Male runners may also wear a bra to prevent chafing on the nipples during runs.
Gynecomastia can occur as the result of obesity, drug use, steroid use or as a side effect of prescription medication use. There are bra shops that will work with men to provide discreet fittings. There are also online shops where men can purchase bras.
Some men wear bras to prepare for transgender surgery. Men taking hormones may begin to grow breasts and choose to wear a bra.