Ah, puberty. It can be a very interesting time in a guy's life, what with all the changes going on. In fact, it seems like every day something on your body grows bigger or hair begins sprouting somewhere. Each day brings a new change or two, and it can sometimes feel like it's hard to keep up. It doesn't happen to every guy, but one of these changes can be the development of breast tissue.

Gynecomastia also spelled gynaecomastia [a] is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogen and androgen. Gynecomastia can be normal in newborn babies due to exposure to estrogen from the mother, in adolescents going through puberty , and in older and obese men. Alcohol and some drugs can also cause breast enlargement. Gynecomastia is different from " pseudogynecomastia ", [5] [6] which is commonly present in men with obesity. Medications such as aromatase inhibitors have been found to be effective [15] and even in rare cases of gynecomastia from disorders such as aromatase excess syndrome or Peutz—Jeghers syndrome , [16] but surgical removal of the excess tissue can be needed to correct the condition.

Back to Men's health. Gynaecomastia sometimes referred to as "man boobs" is a common condition that causes boys' and men's breasts to swell and become larger than normal. It is most common in teenage boys and older men. Signs vary from a small amount of extra tissue around the nipples to more prominent breasts.