Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 2/23/2022
"Morning wood" is a not-so-medical slang term that just about every man is familiar with -- a morning erection. The clinical term for the erections we wake up with in the morning is more specific and more than a little harder to remember: "nocturnal penile tumescence."
As a man, it’s easy to get used to waking up with an erection. In fact, most of us take morning wood for granted, making it a bit of a shock to one day wake up without one.
Morning erections are completely normal and healthy. They’re an important sign that you have good sexual function. Being able to get a morning erection is a helpful indicator that your heart, blood vessels and nervous system are functioning properly.
On the other hand, the absence of morning wood can potentially be a sign that you’re starting to develop a sexual health issue, such as erectile dysfunction (ED).
Below, we’ve explained why morning erections happen, as well as what they generally mean for your sexual function and overall health. We’ve also discussed what a lack of morning wood may mean for your sexual performance and wellbeing as a man.
Morning wood is an easy-to-remember, colloquial term for nocturnal penile tumescence. If you get nocturnal erections (erections that happen while you’re asleep), there’s a good chance that you’ll wake up from time to time with morning wood.
Despite its popularity, the term “morning wood” isn’t entirely accurate. While most guys notice their erections when they wake up in the morning, it’s common to get several erections during the night, often for a variety of reasons.
In fact, according to the International Society for Sexual Medicine, most men will get between three and five erections during sleep on a typical night.
Morning wood happens in males of all ages, including children and adolescents. It’s a normal occurrence and isn’t a sign of sexual or health problems. In fact, it’s a good sign that you have normal sexual function and healthy blood flow to your penis.
Experts haven’t yet identified exactly why nocturnal erections occur. However, current theories suggest that several different factors could play a role in morning erections, from the content of your dreams to changes in your hormone levels that occur while you’re sleeping.
At a basic level, erections occur when your nervous system increases the blood supply to your penis, allowing blood to flow into your erectile tissue. As blood pressure increases, your penis becomes firmer, creating an erection.
This can occur when you’re awake, such as during sex or masturbation, or in certain stages of your nightly sleep cycle.
Most of the time, nighttime erections develop as a result of mental stimulation, such as imagery from your dreams.
Human sleep involves several distinct and unique stages, from N1 (the lightest sleep stage) to N3 (the deepest stage of sleep). As your body exits the deeper sleep of N3, it moves into rapid eye movement sleep, or REM sleep.
During REM sleep, your parasympathetic nervous system remains highly active, meaning many of your involuntary bodily functions continue to occur while you’re sleeping.
If you have a sexually stimulating dream, it may cause you to develop an erection during REM sleep. It’s common and normal to get and lose your erection a few times throughout the night, not just before you wake up.
When nighttime erections happen as a result of sexual dreams, they can even lead to nocturnal ejaculation.
Your levels of testosterone -- the primary male sex hormone -- gradually increase as you sleep, often by quite a significant amount.
In one study, researchers found that men’s testosterone levels increased from 15.3 ± 2.1 to 25.3 ± 2.2 nmol/liter during night sleep.
This increase in testosterone levels may be a factor in morning erections, as research suggests that higher levels of testosterone are usually associated with higher scores on tests of nocturnal penile tumescence.
There might also be a physical component to morning wood. While you sleep, physical contact with your partner (or even just pressure from your sheets, pillow or clothing) may stipulate your penis and cause you to develop an erection.
Erections are controlled by your sacral nerve -- a collection of nerve pairs that exit your spinal column at the sacral vertebral region, an area at the bottom of your spine.
While many nighttime erections are triggered by sex-related dreams, others may be caused by something much simpler: needing to urinate.
As your bladder fills up with fluid, it can press against the sacral nerve and stimulate it, causing an erection to develop. This type of erection is often referred to as a “reflex erection,” as it isn’t directly caused by sexual stimulation.
Morning erections are a normal part of life. Far from being unhealthy or bad, they’re actually an extremely reliable indicator that your body is physically capable of getting an erection, meaning you aren’t affected by physical erectile dysfunction.
Erections depend on healthy nerves and blood vessels. If you can get an erection while you’re asleep, it’s a good sign that you’re physically healthy enough to get one while you’re awake.
Just like morning wood is normal, it’s also perfectly common and normal to sometimes wake up without an erection. Occasionally, you’ll snap out of your sleep at the “wrong” moment and wake up without an erection. As long as it’s only occasional, it’s usually not a problem.
However, if you often wake up without an erection, or if you notice a sudden drop in nighttime or morning erections, it could be a sign of an underlying health issue that’s causing ED.
Erectile dysfunction has a range of potential causes. Common physical health issues that cause or contribute to erectile dysfunction include:
Heart and blood vessel disease
Atherosclerosis (clogged arteries)
Hypertension (high blood pressure)
Injuries to your penis and surrounding area
Complications from surgery
Chronic kidney disease
Type 2 diabetes
Some prescription drugs, such as antiandrogens, antidepressants, blood pressure medications, tranquilizers, ulcer medications and appetite suppressants, may also contribute to ED and stop you from getting nighttime erections.
Erectile dysfunction can also develop as a result of psychological issues, such as anxiety about sex, depression, chronic stress and low self-esteem.
If you often wake up without an erection and find it difficult to get an erection during the day, it’s best to talk to a health professional.
Erectile dysfunction is almost always treatable. Most of the time, medications like sildenafil (the active ingredient in Viagra®), tadalafil (Cialis®) and avanafil (Stendra®) can restore your sexual function and make it easier for you to get an erection before and during sex.
These drugs belong to a class of medications called PDE5 inhibitors, which work by increasing the flow of blood to your penis.
We offer several FDA-approved erectile dysfunction medications online, following a consultation with a healthcare provider who will determine if a prescription is appropriate.
Sometimes, simple changes to your habits and lifestyle can also improve your sexual health and make getting morning wood easier. Try to:
Keep yourself physically active. Even a small amount of daily exercise can have a noticeable impact on your cardiovascular health and ability to maintain an erection. Try to get at least 150 minutes of moderate-intensity exercise per week.
Maintain a healthy body weight. Obesity is a risk factor for erectile dysfunction, with men in the obese BMI range around three times more likely to develop ED than men in the normal range.
Limit your alcohol consumption. Research shows that drinking alcohol often and in large quantities is associated with ED and other sexual performance problems. Try to limit your alcohol consumption to no more than two drinks per day.
Avoid illicit drugs. Some recreational drugs can affect your sexual function, including your ability to get an erection. If you have a substance use disorder, talk to a healthcare provider about receiving professional care.
Quit smoking. If you smoke, consider quitting. Research shows that smokers have an elevated risk of developing erectile dysfunction due to the negative effects of smoking on cardiovascular health.
Our guide to naturally protecting your erection shares other techniques that you can use to treat ED and improve your sexual performance naturally.
Morning erections are a normal part of life and a helpful signal that you’re physically capable of getting an erection. If you’ve recently stopped getting morning wood, it could be a sign that you have an underlying physical or psychological issue that’s causing ED.
The good news is that ED is almost always treatable, typically with medication and some minor changes to your habits and lifestyle
We offer a range of ED treatments online, including evidence-based medicine available after an online consultation with a healthcare provider.
Interested in learning more about erectile dysfunction and sexual health? Our guide to the most common treatments and drugs for ED goes into more detail about how you can maintain healthy erections and optimal sexual performance at any age.