Male breast development, known scientifically as Gynaecomastia, is defined as excessive development or growth of the male breast. This condition affects up to 36% of males and usually affects both breasts. The cause of the male breast enlargement is usually a hormonal imbalance, with relative reduction of male hormones (androgens) and relative excess of female hormones (estrogens). In majority of patients, the cause of this imbalance remains unknown, with most patients having a normal hormonal profile.