In boys, the mammary glands have degenerated and serve no physiological purpose. However, there is an abundance of nerve distribution in the nipple, which produces physical sensations that affect mood. Unlike females, male mammary glands do not develop and gradually shrink during pubertal development due to differences in hormone levels. As a result, the chest of an adult male is essentially flat, but the male breast has an abundance of nerves around the nipple, and when stimulated, these nerves transmit sensations to the brain, which creates an emotional response. Most importantly, it increases male arousal during sex. Normal male chest can only see the nipple and areola, does not have the physiological function of lactation, but as one of the human body organs, missing breasts will directly affect the integrity of the human body, resulting in aesthetic incongruity and psychological discomfort.