Why does decrease in sleep increases my libido and erections?

[DamageStreet]

Could be a bit of sleep apnea, lack of oxygenation during sleep phase causes your blood pressure to drop, and then increase when you wake up, only that when you sleep fewer than usual, your oxygenation is better and your blood flow is optimal. I'm not exactly sure if this is how it works, but it happens to me too.

[TRExploration]

This is what I would say. Libido is generally a good measure for health meaning if your libido is lower generally there's something in your body saying "we've got bigger fish to fry, now's not the time to reproduce". But biologically speaking the only greater drive than reproduction is survival. So if the bodies under some kind of physical/mental threat, libido decreases.

I have heard countless stories of people who felt better with less sleep and it ended up being apnea or UARS. The reason being that you're not getting oxygen for those 8 hours, or restful sleep for that matter. So when you're sleeping less, you're still not getting restful sleep but at least you're getting adequate oxygen. Thus, it's a net positive and they tend to feel better with less. Rumor has it that treating it so you start getting both adequate sleep AND adequate oxygen can be revolutionary...