Diagnosing secondary hypogonadism: important consequences for fertility and reversibility.

Hypogonadism (HG, testicular failure in men) has become a controversial and much misunderstood condition. Many men perceive testosterone as a panacea for the ills of ageing and "Low-T clinics" have sprung up to meet their demands, even though testosterone is often not the answer. In light of the unprecedented rise in testosterone prescriptions in recent years, particularly amongst middle-aged men, the US Food and Drug Administration (FDA) issued a Safety Communication in May 2015 intended to restrict the use of testosterone.