In general, male bras are loosely placed into one of two categories: compression bras and bras used for cross-dressing and sexual fetishes. A male bra used for compression is normally meant to flatten the breasts and is made from a stretchable fabric. These bras typically do not lift the breasts; their primary purpose is usually to minimize the appearance of overly large male breasts. Bras used for cross-dressing and similar purposes sometimes more closely resemble the female bra. Besides being called a male bra, compression bra, or compression vest, these types of bras are occasionally referred to as bros.
Depending on the type of male bra, the construction of the garment varies significantly, sometimes not resembling the female counterpart at all. A compression bra is typically made from a stretchable fabric like spandex and may cover the entire torso and part of the legs. Normally, its goal is to reduce the appearance of the breasts, but it might also take on the role of flattening the stomach and giving the thighs a tighter appearance. Cross-dressing bras, on the other hand, often lift the male breasts and increase cup size to give the man a more feminine figure. They may also have designs similar to some female bras, with colorful fabric, lace, and ruffles.
Some men use a male bra to reduce the size of breasts that have developed on their bodies due to either obesity or other medical complications. These men will typically use their male bra to support their breasts similarly to how women typically use their bras. The notable difference between how men often use a supportive bra compared to how women do is that this use of a male bra will typically seek to flatten and reduce possible attention to the breasts, while female bras often do the opposite. Another common use of the male bra is as an accessory for sexual fetishes, as when a man seeks to dress up as a woman. As breasts are generally considered an important and identifiable facet of the female form, men who dress up as women often consider a bra to be an indispensable part of their wardrobe.
Wearing a male compression bra is essentially a form of breast binding, which has been done for thousands of years by both men and women. Women bound their breasts to flatten them for a variety of reasons, such as making their breasts less distracting to better fulfill their lives as Catholic nuns and as a fashion statement when flat-chestedness and small breasts were popular.