Boys wearing short sleeves may be caused by muscle development or fat accumulation. Specifically, if the male muscle lines are obvious, especially the upper limb muscles, then the muscle bulge may be more prominent when wearing short sleeves. In addition, if a man's lower abdomen or upper body is full, wearing short sleeves may also appear protruding.

Therefore, boys wearing short-sleeved shirts does not necessarily mean being strong or obese, and it needs to be judged according to specific circumstances. If men have a well-proportioned figure and a healthy overall figure, then wearing a short-sleeved shirt may be just one of the personal figure characteristics, so don't worry too much. If the male figure is disproportionate, the overall figure is too fat or the bulge is unusually prominent, then corresponding health management measures may be needed to improve his physical condition.