Ans. B: Hypothyroidism Gynecomastia results from an imbalance in hormone levels in which levels of estrogen are increased relative to levels of androgens. Gynecomastia that occurs in normally-growing infant and pubeal boys that resolves on its own with time is known as physiologic gynecomastia. A number of medical conditions may also result in gynecomastia: Malnutrition and re-feeding (recovery from malnutrition) have both been shown to create a hormonal environment that may lead to gynecomastia. Similarly, cirrhosis of the liver alters normal hormone metabolism and may lead to gynecomastia. Disorders of the male sex organs (testes) can result in decreased testosterone production and relatively high estrogen levels, leading to gynecomastia. These disorders may be genetic, such as Klinefelter's syndrome, or acquired due to trauma, infection, reduced blood flow, or aging. Testicular cancers may also secrete hormones that cause gynecomastia. Other conditions that are associated with an altered hormonal environment in the body and may be associated with gynecomastia are chronic renal failure and hypehyroidism. Gynecomastia can also be a side effect of a number of medications. Examples of drugs that can be associated with gynecomastia are listed below: -- Spironolactone- it has anti-androgenic activity; - Calcium channel blockers used to treat hypeension (such as nifedipine); - ACE inhibitor drugs for hypeension (captopril, enalapril); - Some antibiotics (for example, isoniazid, ketoconazole, and metronidazole); - Anti-ulcer drugs (such as ranitidine, cimetidine, and omeprazole); - Anti-androgen or estrogen therapies for prostate cancer; - Methyldopa; - Highly active anti-retroviral therapy (HAA) for HIV disease, which may cause fat redistribution leading to Pseudogynecomastia or, in some cases, true gynecomastia; - Digitoxin; - Diazepam