Low testosterone (male hypogonadism) is a condition in which the testes (testicles, the male reproductive glands) do not produce enough testosterone (a male sex hormone).
In men, testosterone helps maintain and develop:
As a man ages, the amount of testosterone in his body gradually drops. This natural decline starts after age 30 and continues (about 1% per year) throughout his life.
There are many other potential causes of low testosterone, including the following:
Symptoms of low testosterone depend on the age of person, and include the following:
Other changes that occur with low testosterone include: