Men Home > What Causes Low Testosterone?
Low testosterone levels occur when there are insufficient amounts of the male hormone called testosterone. But what causes this?
In general, low testosterone can be caused by problems in the testes, pituitary gland, or hypothalamus. If the problem is due to the testes, it is called primary male hypogonadism. If the problem is with the pituitary gland or the hypothalamus, it is called secondary male hypogonadism.
Some of the possible causes of low testosterone that are attributable to problems with the testes include:
- Undescended testicles (cryptorchidism)
- Abnormal enlargement of the vein within the scrotum (varicocele)
- Injury to the testes.
If the problem is due to the hypothalamus or the pituitary gland, some causes may include:
- High levels of the hormone prolactin (hyperprolactinemia)
- Infection or injury in the brain or brainstem.
(Click Causes of Low Testosterone for an in-depth look at what causes low testosterone levels and how your healthcare provider will determine whether the cause is primary or secondary.)