What does it mean to wake up with an erection

You must have heard of morning wood before, a slang term used to describe the presence of an erect penis upon waking. However, it is medically known as nocturnal penile tumescence (NPT). NPT commonly occurs in boys and men but it has a higher occurrence in younger men. 

NPT is commonly assumed to be a sign of sexual stimulation, however, there are other reasons behind it. It is the normal function of the male reproduction system. Your body’s normal response to natural occurrences results in morning wood. 

Who gets morning wood?

There is no age limit for men to get NPT. Men of all ages can experience it. It is a good sign for men of any age to get a morning erection. The regular occurrence of NPT is a good sign of healthy nerves and blood supply to the penis. From young boys, aged 6-8, to older men in their 60s and 70s can have NPT. However, if you experience erectile dysfunction, the frequency of these erections will be lower.



The parasympathetic nervous system, specifically the sacral nerve, controls erections. When your body is relaxing and repairing itself, your parasympathetic nervous system is active. The parasympathetic nervous system is in charge of digestion, waste removal and sexual arousal. On the contrary, the sympathetic nervous system is what is activates during fight and flight situations. 

NPT commonly occurs during the phase of sleep called REM sleep. REM sleep is called rapid eye movement and this phase usually happens 80-110 minutes into sleep. Normal sleep patterns referred to as sleep architecture, go through transitions of different sleep stages throughout the night. When morning comes about, the REM sleep period is prolonged, with the last third of the night mainly spent in REM sleep. Hence, when you wake up, you are often coming out of REM sleep. 

During REM sleep, the penis is also erect and full of blood due to the parasympathetic nervous system activation during sleep. This is a reason as to why erections occur occasionally during sleep. The penis goes through cycles or erection and flaccid during sleep. Erections usually disappear after a few minutes upon waking. It may even be possible for the clitoris of the women to be rushed with blood during REM sleep. 


Persistent painful erections

Morning wood should usually disappear 30 minutes after waking up. A persistent erection occurs where the blood fails to drain from the erect penis and is known as priapism. These erections lask more than an hour after waking and are usually very painful. If you experience priapism lasting more than 4 hours, it is imperative to seek emergency medical attention.


No morning wood?

As one gets older, NPT happens less regularly. This may be linked to impotence that occurs during the day. On the other hand, the occurrence of NPT with impotence in the day can point towards non-physiological causes of erectile dysfunction. These non-physiological factors can be stress or performance anxiety. 

It is not abnormal to wake up without morning wood, it can just mean you did not wake up during the REM sleep phase. Another reason might be that the erection began fading before waking up fully. 


Time to see the doctor

NPT is a good indicator of the general health status of your body. By paying attention to it, it can tell you more about your quality of sleep and sexual organ health. If there is a sudden change regarding the frequency of the morning erection, it is good to consult your doctor. The change can indicate the presence of a sleep disorder, hormone imbalance, anxiety or erectile dysfunction. The lack of regular NPTs can indicate problems with the nerves and blood supply in the penis and other male reproductive organs. 

Certain medications can also contribute to the lack of or maintenance of NPT. Some of these medications include:

  • High blood pressure medication 
  • Muscle relaxers
  • Hormonal medications 
  • Seizure medications 
  • Antidepressants
  • Histamine H2 agonist 
  • Chemotherapy drugs
  • Medications to treat heart arrhythmias 
  • Diuretics

If you notice a change in the frequency or lack of NPT after starting any of these medications, you might want to seek medical advice from your doctor. Sometimes, they might switch your medication to get rid of this side effect. 



There’s nothing to worry about or be shy. NPT or morning wood is a completely normal and healthy phenomenon in men. It is a good indicator of decent blood and nerve supply to the penis. It is common to experience NPT several times a week. As men age, it is also normal to experience NPT less frequently. 

If you notice a sudden change in the frequency of these erections, do talk to your doctor. This way, if there are any underlying conditions it can be treated immediately. 



The REM Sleep Stage May Play a Role in Causing Erections". in , , 2020, <https://www.verywellhealth.com/what-causes-morning-wood-or-morning-erections-3015089> [accessed 17 March 2020].

Why Do Men Get Morning Erections? 5 Answers to Your Questions". in , , 2020, <https://health.clevelandclinic.org/men-get-morning-erections-5-answers-questions/> [accessed 17 March 2020].

Morning wood: Causes and frequency". in , , 2020, <https://www.medicalnewstoday.com/articles/325305#summary> [accessed 17 March 2020].

What Causes Morning Wood?". in , , 2020, <https://www.healthline.com/health/mens-health/morning-wood#who-gets-morning-wood> [accessed 17 March 2020].