Hypogonadism Diagnosis and Hormonal Axis

Understanding Secondary Hypogonadism

The combination of low estradiol and low free testosterone suggests secondary (central) hypogonadism, where FSH levels remain low or inappropriately normal despite low sex steroids, as indicated by the Endocrine Society 1, 2, 3
Low testosterone with concomitantly low LH/FSH indicates secondary hypogonadism, according to the American Urological Association 1, 2, 3
This pattern of low free testosterone and low estradiol with low/normal FSH is consistent with secondary hypogonadism, as noted by the Journal of Urology 4

Measuring morning LH and FSH levels (8-10 AM) can distinguish primary from secondary hypogonadism, as recommended by the American Diabetes Association and other societies 1, 2, 3, 7
Low or inappropriately normal LH/FSH with low testosterone confirms secondary hypogonadism, according to the Endocrine Society and the Journal of Urology 1, 2, 3, 4
Measuring serum prolactin in patients with low testosterone and low/normal LH can screen for hyperprolactinemia, as suggested by the American Diabetes Association 7