Man Boobs Causes Explained: Enlargement or sagging breasts of men is a common problem, which is called Gynecomastia in medical language. This condition arises when there is an imbalance of estrogen and testosterone in the body of men. Due to hormonal disturbances, the size of the mammary glands starts increasing. Obesity is also a major reason for man boobs. Due to accumulation of excess fat in the body, fat increases around the chest, which people often mistake for gynecomastia, whereas in many cases it is just fat deposit. To prevent and treat this problem, it is important to identify the correct cause. Men can get rid of this problem with timely diagnosis and treatment.