Gynecomastia is characterized by the development of swollen or enlarged breasts. Even though it is a common condition, it can make life difficult. It can afflict men of varying age, and adolescent cases resolve within a short span. There is no exact cause of this condition however some drug side effects are known to contribute to enlarged male breasts. Additionally, gynecomastia is also linked to hormonal imbalances (particularly during puberty), steroid use, genetics, obesity and use of marijuana.