Morning wood, also known as nocturnal penile tumescence (NPT), refers to the phenomenon of having an erection upon waking up in the morning. It is a normal physiological response that typically occurs during the REM (rapid eye movement) sleep stage when males experience multiple erections throughout the night, usually lasting for a few minutes to an hour. Morning wood is a sign that the male reproductive system is functioning properly and is often unrelated to sexual arousal or dreaming.
