Some medical conditions may also lead to gynecomastia:
Malnutrition and (recovery from) malnutrition have been shown to create a hormonal milieu that may lead to gynecomastia. Similarly, cirrhosis of the liver alters the normal metabolism of hormones and may lead to gynecomastia.
Disorders of the male sex organs (testicles) can lead to decreased testosterone production and relatively high levels of estrogen, leading to gynecomastia in men. These disorders may be genetic, such as Klinefelter syndrome, or caused by trauma, infection, decreased blood flow, or aging.
Testicular cancers may also produce hormones that cause gynecomastia.
Chronic kidney failure and hyperthyroidism are other conditions that are associated with changing the hormonal environment in the body and may be associated with gynecomastia.
Rarely, cancers other than testicular tumors may produce hormones that can cause gynecomastia.