Nocturnal erection, also medically called nocturnal penile tumescence (NPT), indicates erections occurring at night without any sexual stimulation. It is usual for men to have three to five erections in an eight-hour sleep, with each erection lasting to about half an hour. Erections usually occur during rapid eye movement sleep when there is only little production of norepinephrine, which prevents erection by stopping blood flow.
Morning Wood - Is It Normal?
Morning wood, or nocturnal penile tumescence, is an erection in the early morning, usually before fully awakening. Read on more to know about it.
