Drug therapy and abnormal liver functioning can also be causes of gynecomastia in older men. When the disease is pathologic, the patient can have increased estrogen secretions, increased conversion of androgens to estrogens, or decreased androgen activity due to a failure in protein receptors. Increased estrogen secretions are found in such diseases and disorders as Hermaphroditism, Kleinfelter's syndrome, congenital adrenal hyperlasia, and adrenal carcinoma or testicular tumors. In the second case some examples are adrenal carcinoma, liver disorders, malnutrition and thyroidtoxicosis. Decreased androgen activity can be found in complete testicular feminization, incomplete testicular feminization and Reifenstein's syndrome.
Many drugs can cause gynecomastia by several mechanisms.
The drugs can either act directly as estrogens or cause and increase in plasma estrogen levels. Use of these drugs, however, will rarely cause gynecomastia. In some instances, the feminization is due to effects of drugs on liver functions. There are very few signs and symptoms that are associated with this disease. Signs may appear at any time in a male's life, although the most common time of onset is during puberty.