Why Do I Get Erections During the Night?

Health Professional

In the context of testing for erections during the night, you stated that this is a normal male function. I can't seem to find anyone who will tell me what causes erections during the night. I know they are not sexually stimulated, and remember that this has been a phenomenon of being male since long before sex was in the picture for me. Can you help me understand what is happening at night to cause an erection?

Overnight erections occur during various phases of the sleep cycle. They most likely occur during the phase of sleep known as REM (rapid eye movement sleep). Patients who demonstrate erectile activity during sleep, and are not able to obtain erections with a partner, are most likely suffering from psychogenic erectile dysfunction. Sleep testing , Nocturnal Penile Tumescence (NPT), is often utilized to help make this distinction.

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