What causes low testosterone in men. you say it is not small testes?

Many causes: There are many causes for low testosterone. They include testicular atrophy (small testes that develop), testicular dysgenesis (a genetic illness), stress, diabetes, alcoholism, marijuana use- to mention a few. You should see your physician to sort this out.

Many things: Prior use of body-building steroids, pituitary disease, testicular injury, mumps, diabetes, age to name a few. Small testes can be a clue as to the cause, but is not the cause itself.

Bad luck . . .: In addition to the other answers, long-term narcotic used to treat chronic pain has also been associated w/hypogonadism or low testosterone. When appropriately treated w/testosterone replacement, there have been reports of being able to decrease narcotic dose.

Pituitary & testis: Pituitary produces luteinizing hormone which stimulates leydig cells in the testis to produce testosterone.Level of testosterone acts on hypothalamus of brain regarding secretion of gonadotropin releasing hormone which inturn stimulates lh production.Low t stimulates gnrh secretion, high t supresses.Thus low t can be due to pituitary or hypothalamus problem or primary from testicular leydig cells.

Varies: It can be from prior injury, testicular failure (they quit working), or loss of signal to tell the testicles to work. There are many diseases that contribute like diabetes, pituitary tumors, steroid use and chronic pain meds. It's more complex than can be listed here. Make sure it's been checked in the morning and if it's really low, see your urologist. For more: www.Peedoc.Com @thepeedoc.

Obesity and zinc def: Obesity and zinc deficiency are the two most common causes in my practice. Zinc is essential for testosterone synthesis, and i would encourage all low-t males to take supplemental zinc. Obesity is now more common, because fat cells contain cyclic aromatase, which converts testosterone to estradiol, which turns off the pituitary glands production of fsh and lh!