Morning wood is slang for the early morning erections that are frequently present among men. Erections, or penile tumescence, occur during the sleep stage called rapid eye movement (REM) sleep. Sleep is often a balance between two parts of the autonomic nervous system, divided into the sympathetic and parasympathetic systems. It seems that during the REM phase of sleep, the body’s systems are tested, including the function of the erectile tissue within the penis. The parasympathetic nerves trigger the tissues to become engorged with blood, and then firm. This phenomenon can even be observed among infants. As the last REM period often occurs right upon awakening, men will frequently wake with an erection. What if this does not occur?
There are a few reasons that a man may not wake up with a morning erection. First, younger adolescent boys who are not fully capable of erections will not likely have one upon awakening. These erections may occur with increasing frequency later in puberty, and into adult life. Men may not wake with an erection if they're not coming out of REM sleep at that time. Wakefulness is often preceded by lighter stages of sleep when erections do not occur. It's also possible to have REM without having an erection. A lack of morning erections may also be a sign of erectile dysfunction (ED) or impotence.
Men with erectile dysfunction or impotence may not be capable of having an erection. Alternatively, they may have an erection that is not firm enough to achieve penetration. Erectile dysfunction may be related to a physiological or psychological process, and a lack of morning wood may help to differentiate between these causes.
Physiological causes of impotence relate to an underlying inability to fill the penis with blood to make it erect. This often has a vascular cause, meaning that it relates to dysfunction of the blood vessels. It may also occur as a side effect to medications, most commonly antidepressants. Men with a physiological cause of impotence will not have morning wood. Alternatively, some men are not able to become erect due to a psychological difficulty. A lack of sexual arousal or responsiveness may lead to impotence. This can also occur because of anxiety. Men with a psychological cause for erectile dysfunction will still have morning erections, since they are physically capable of having them.
Therefore, men who suffer from periods of impotence who still have morning wood likely have a psychological cause for their erectile dysfunction. Those who are unable to achieve an erection at any time may have a physiological cause to their condition. A lack of morning wood may not necessarily represent a problem, however, as it doesn't occur daily in all men for the reasons described above.
If you are concerned about difficulty achieving or maintaining an erection, you should speak with your health care provider. It will be important to convey whether you have morning erections, as this may provide insight into the underlying cause of your problem. Fortunately, there are a number of effective treatments for erectile dysfunction; you just have to speak up to your doctor.