True gynecomastia (enlarged male breast) is a condition resulting from imbalance between testosterone and estrogen production.
Although many people think that estrogen is a female hormone, men also produce it (although in much smaller quantities). Since estrogen is a hormone controlling the growth of breast (among other roles), its overproduction or imbalance with testosterone (male hormone) may result in enlarged breast gland in males. This is different than male breast enlargement in obesity, where the enlarged breast consists mostly of fatty tissue accumulation.
Before & after photos coming soon.