Male hypogonadism is surprisingly common, affecting about 1 in 3 men over 45. There are two main types: primary and secondary hypogonadism. One type starts in the testes, while the other has to do ...

Hypogonadism is when the sex glands (gonads) produce little or no sex hormones. Low sex hormone levels (testosterone and estrogen) lead to low energy, decreased sex drive, and conditions like ...

In men, marked hypogonadism due to pituitary or testicular disease generally has readily recognizable clinical manifestations, such as decreases in libido and sexual activity, loss of secondary sex ...

The Nature Index 2025 Research Leaders — previously known as Annual Tables — reveal the leading institutions and countries/territories in the natural and health sciences, according to their output in ...