What Is
Gynecomastia?
Gynecomastia is a condition wherein glandular tissue excessively develops in males. It can be distinguished by the presence of a rubbery and firm mass around the nipples. This physiologic condition can usually be seen in neonates (babies from one to four weeks of birth), adolescents, and the elderly. It can either occur bilaterally or unilaterally, where in only one breast is enlarged.
Testosterone is produced a hundred times more than estrogen, but its amount in circulation that can be seen in blood is about 300:1. In males, estrogen is produced by the conversion of androgens testosterone and androstenedione to estradiol and estrone, the active form of estrogen. The enzyme aromatase found in muscle, skin and adipose tissue is responsible for this interconversion. Other Known Causes Gynecomastia can result from medications, diseases, illegal drugs, alcohol, and aging. It is caused by the following medications: cimetidine (an H2 antagonist), omeprazole (a benzoimidazole), spironolactone (an aldosterone antagonist), imatinib mesylate, finasteride (a nitrogenous steroid derivative used to treat symptoms of benign prostatic hyperplasia and to increase hair growth in male-pattern baldness) and anti-psychotic drugs. Finasteride acts by inhibiting the enzymatic conversion of testosterone to dihydrotestosterone, which lowers the circulating serum/blood level of testosterone. Anti-androgens such and gonadotropin-releasing hormone (GnRH), which is used for treating prostate cancers also has the same effect. Other medications act mainly on the breast tissue
which
causes enlargement, or to increased circulation of prolactin (a hormone
which
causes breast development) production from the pituitary gland. It may
also be
caused by inhibiting dopamine, which is a natural prolactin-inhibiting
factor
in males. Performance enhancing food supplements, such as
androstenedione, can
also lead to breast enlargement by increasing estrogen action.
All of these things can make men self conscious and want to get
rid of man boobs. Gynecomastia may also be caused by defects in androgen receptors (inability of the cell to recognize androgens) as seen in Kennedy disease, chronic kidney disease, chronic liver disease, HIV, and other chronic diseases. Tumors of the adrenal glands, testes, pituitary glands, as well as hyperthyroidism and hypogonadism also have the same effect. The part of the pituitary gland affected will mostly involve the anterior portion because this is the part that controls prolactin, growth hormone, and TSH (thyroid stimulating hormone). Diseases of the hypothalamus can also lead to low testosterone levels. Adrenal tumors cause increased androstenedione levels. In obesity, there is there increase of estrogen levels. In liver cirrhosis,
there is decreased estrogen clearance
or breakdown, thus estrogen tends to stay in the body, which may lead
to
gynecomastia. Decreased testosterone production may also occur in
genetic
disorders such as Kleinfelter syndrome. Abuse of illegal drugs such as
amphetamines, heroin, marijuana and anabolic steroids also cause
gynecomastia.
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