Typically, men have several erections while they sleep. The process is called nocturnal penile tumescence (NPT) (or “morning wood” in slang terminology), and it occurs in males of all ages, even small children. These erections are not caused by sexual stimulation but seem to be associated with REM (rapid eye movement) sleep.
If a man wakes up during or just following an REM sleep period, he might have a morning erection.
The lack of a morning erection isn’t necessarily a concern. Sometimes, men wake up at different points in a sleep cycle, when an erection isn’t occurring.
Still, morning erections might provide some clues about erectile dysfunction (ED). ED can have physical and psychological causes. Sometimes, both physical and psychological factors are involved at the same time.
When a man suspects he has ED, his doctor might ask about morning erections. If he still experiences NPT, chances are his erection problems have a psychological origin, since his physical “plumbing” is still in working order. If he doesn’t have NPT, then physical issues may be the root of the problem.
Morning erections are not the only criteria used to assess ED, however. Doctors will also consider a man’s medical history, testosterone levels, and any medications he takes. (Learn more here.)
Men who find that they don’t have morning erections the way they used to should mention the situation to their doctor.
“Why Do Men Get Morning Erections? 5 Answers to Your Questions”
(June 22, 2016)
International Society for Sexual Medicine
“What is nocturnal penile tumescence (NPT)?”
“Nocturnal Penile Tumescence”
Peters, Brandon, MD
“Lack of Morning Wood Erections”
(February 23, 2018)