Nocturnal penile tumescence (NPT) is not a result of sexual arousal or having a dream relating to sex. Instead, it is a normal function of the male reproductive system.
In fact, regular episodes of NPT are a sign that the nerves and blood supply to the penis are healthy.
If a male does not have NPT regularly, it can indicate a health issue, such as erectile dysfunction (ED), which involves having trouble getting or keeping an erection. Not having regular NPT can also suggest other problems with the nerves or the blood supply to the male reproductive organs.
A hormonal imbalance, such as a decrease in testosterone, can also affect how often a person experiences NPT. A lack of regular NPT can sometimes result from not getting quality sleep.
As a person gets older, they can expect to experience NPT less often. This change should happen gradually, as hormone levels shift. Anyone who notices a sudden drop in the number of their NPT episodes should speak with a doctor to rule out any potential health issues.
Causes
“Morning wood” is a common occurrence for most men.
NPT is not a typical erection because it is not related to sexual thoughts, dreams, or stimulation. It is simply a result of sleep cycles, combined with healthy nerves and blood flow in the body.
NPT tends to happen when a person is in a rapid eye movement (REM) phase of sleep. REM sleep can occur several times during an 8-hour sleep cycle. The erection may go away on its own as a person enters deeper sleep. Thus, a person may have erections several times during the night but may not be aware of them.
Often, a person wakes up at the end of a REM sleep cycle, which explains why NPT seems to happen in the morning. In addition, testosterone levels tend to be elevated in the morning. Males have high levels of this hormone, which contributes to sexual function.
An erection caused by NPT may be physically different from one caused by arousal. One study found that some men experienced pain when they had NPT, but not when they had typical erections.
How often should morning wood occur?
Males of various ages, from children to older adults, experience NPT. Usually, younger adults, who have the highest levels of testosterone, will experience nocturnal erections more frequently than children or older people. Young adult males may have NPT every morning and a few times during the night.
The peak of sexual maturity generally happens when males are in their late teens to late 30s, and this may correspond with higher testosterone levels. It is normal for people in this age range to experience frequent episodes of NPT.
As a person approaches their 40s and 50s, they may notice fewer episodes of NPT. This often occurs because testosterone levels are naturally declining. However, the episodes should decline gradually, not suddenly. A gradual decline in NPT with age is customary.
A hormonal imbalance, especially one that affects the penis and testes, can result in few or no episodes of NPT. This is one reason why having regular erections in the morning is an important indicator of healthy male sexual organs.
One study found that men with hypogonadism, which prevents the sexual organs from fully functioning, experienced an increase in NPT after they had received testosterone therapy.
Some research says that a person’s quality of sleep can affect the frequency of NPT. If a person is not getting good sleep and entering the REM cycle, they may not experience nocturnal erections.
A study of 61 men with obstructive sleep apnea and ED found that getting better quality sleep resulted in more frequent NPT. The participants who used continuous positive airway pressure devices had more frequent nocturnal erections than those who did not.
Other studies have used NPT as an indicator of hormonal or sexual health, especially when treating ED.
For instance, if a person has NPT but cannot get or maintain an erection during sexual activity, doctors can rule out issues such as insufficient blood flow or nerve responses in the penis. If this is the case, ED may be a psychological issue, and a health professional can treat it accordingly.
However, if a person has no nocturnal erections and has trouble getting or keeping erections related to sex, doctors may determine that there is a physical cause of ED.
When to see a doctor
A person should speak to a doctor if they notice changes in how frequently NPT occurs.
Because NPT is an indicator of quality sleep and the health of sexual organs, it is helpful to pay attention to how often NPT happens.
If NPT suddenly stops or is happening much less frequently, speak with a doctor. They may wish to discuss possible health conditions, such as sleep disorders, hormonal imbalances, anxiety, and ED.
It is important to see a doctor about a lack of NPT, as it can be a symptom of ED. This condition can indicate serious health issues, such as heart disease, high blood pressure, or diabetes, especially in younger males. A health professional can help treat these conditions, including ED.
Certain medications, such as antidepressants, can make it more difficult for a person to get or maintain an erection. They may also cause a decrease or sudden stop in NPT. Some of these medications include:
- high blood pressure medications
- muscle relaxers
- hormonal medications
- seizure medications
- antidepressants
- histamine H2 agonists (which can help treat some types of ulcers)
- chemotherapy drugs
- medications to treat heart arrhythmias
- diuretics
If a person has recently started a new medication and notices changes in the frequency of NPT, they may wish to speak with their doctor. Sometimes, the doctor can prescribe a different medication to help address this side effect.
See a doctor if NPT or erections in general are painful.
Seek emergency medical help for an erection that does not go away after 4 hours. If this occurs, it can cause tissue damage in the penis and problems with sexual function.
Summary
Morning wood is a healthy function of the male body.
A person should talk with their doctor if they notice a sudden change in the frequency of nighttime erections. This can ensure that a person receives prompt treatment for any underlying health conditions.
