Gynecomastia is a relatively common problem affecting males of all ages.\u00a0 While some males who present with gynecomastia have no identifiable cause for their gynecomastia, it is not to say that there aren\u2019t known causes of gynecomastia.\u00a0 In fact, there can be many different causes of gynecomastia. In this entry I will categorize the main causes of gynecomastia.<\/p>\n
The broad categories of gynecomastia include endocrine, familial, medication-based. These are quite broad categories and each can be further divided and sub-divided.<\/p>\n
Endocrine causes include any endogenous condition that may increase production of estrogen or testosterone. Some know endocrine causes are thyroid conditions, testicular tumors, and pituitary tumors. It is important to perform a detailed physical exam as well as hormone testing if the clinical suspicion points toward an endocrine cause.<\/p>\n
Familial causes can be specific or non-specific. There are certain genetic conditions which, although quite rare, can lead to gynecomastia. One such condition is Klinefelter\u2019s syndrome. This is a condition where the male has an extra X chromosome which tends to give him more feminine physical traits.<\/p>\n
Of all the known causes of gynecomastia, medications are the most common.\u00a0 Many medications can cause gynecomastia, either through direct increase in estrogen production or in over-production of testosterone. In the latter case, excess testosterone is converted by the body into an estrogen derivative which then has stimulatory effects on the breast tissue. Some examples of this are anabolic steroids, human growth hormone. Other medications that may cause gynecomastia are antidepressants, anti-seizure medications, and certain cardiac medications. Illicit drugs such as marijuana are known to cause gynecomastia when used on a regular basis.<\/p>\n