What Causes Morning Wood?

In this post, we'll be talking about 'morning wood', ‘morning erections’, ‘morning boners’, or whatever other expression you might have heard for waking up in the morning with an erection. We'll be talking about why it happens, whether it's natural to have/not have them, as well as how they may be indicators for your health.


What are Morning Erections?

You might have heard or seen jokes about morning wood on tv and movies, but what exactly is it?

This is when someone wakes up with an erect penis in the morning. The more medical sounding name for it would be Nocturnal Penile Tumescence (NPT) as at night (nocturnal) the penis (penile) gets erect (tumescence). These can happen at any age, and not necessarily every morning.

Whether you've recently had your first morning boner or if you're experiencing drastic changes in how you're having them, it's natural to have questions.

What Causes Morning Wood?

So why is ‘morning glory’ not just a plant, and what is behind this mysterious phenomena?

These types of erection are different from the usual, as they are not caused by sexual reasons.

Instead, it is linked to sleep cycles. Most NPT happens during REM sleep, and as this can happen several times in a night, you may be experiencing repeated erections, without being aware of it. The most common time to wake up is right after REM sleep, this combined with higher testosterone levels in the morning (testosterone being a hormone that triggers erections), means that first thing in the morning is the most likely time to have and notice morning wood.

You might have heard rumors that NPT is the body’s way to prevent urination during sleep, or happens during erotic dreams, however it appears that none of these are true.

Is it Normal to Wake up Without Morning Wood?

Since they are perfectly normal to have, does not having morning erections mean something is wrong?

Since everyone’s body is different, not waking up with morning wood is also perfectly natural. Younger adults have more testosterone, and so would experience it most frequently, and cases could get less frequent as testosterone production decreases in your 40s and 50s.

You should see your doctor if morning erections suddenly stop, or if there is a sudden and noticeable decrease in frequency. Such symptoms could be from other underlying issues such as heart disease (causing problems with blood flow), sleep disorders (stopping REM sleep), and anxiety (a mental cause of erectile dysfunction) among others.

Medication could also have the side effect of stopping NPT, so keep an eye out for that, and speak with your doctor if the changes you notice happen after starting a new course of medication.


Morning wood is a perfectly normal thing to have, and having/not having them every night does not mean too much or too little sexual activity, or that there is anything wrong with your body. Your natural testosterone level, as well as during what point of your sleep cycle you wake up, plays a part in if you wake up with an erection.

Just remember to speak to your doctor if frequency suddenly changes drastically!

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