Hyperprolactinemia can cause symptoms of low testosterone and very low sperm production.

“typically the The Telltale sort of symptoms would be you know ones of low testosterone that's a common one but you know in my practice I see it a lot with men with very low sperm production so I've diagnosed several prolactin secreting tumors and the manifestation of that was you know they weren't getting pregnant we checked a sperm count it was very low you know that mandates a check of testosterone which is also very low and then that leads to a prolactin which is very high and then that that was diagnosed”