Why Do You Have Morning Wood

Why Do You Get Morning Wood? Believe It Or Not, There's an Important Scientific Reason

Why your A.M. boner is important for your health — and what to do if you aren't experiencing it. 

Morning wood, or as it's formally known, nocturnal penile tumescence (NPT), is a common occurrence for many boys and men. From time to time, men may wake up with an erect penis. This is most common in younger men, although men of all ages may experience NPT.

Many people assume a morning erection is a sign of sexual stimulation, however, this isn't always the case. Morning wood is likely the response your body has to one of several natural occurrences.

What causes morning wood?
The cause of NPT is likely multifactorial. Doctors have a few theories that help explain why men wake up with an erect penis from time to time, but none of these theories is supported by concrete, medical evidence. These theories include:

Physical stimulation
Though your eyes are shut, your body is still very much aware of what's happening around you. If you or your partner accidentally touch or graze your genitals, you may become erect. Your body senses the stimulation and responds with an erection.

Hormone shifts
Your testosterone level is at its highest in the morning after you wake up. It is highest immediately after waking up from rapid eye movement (REM) sleep stage. The increase in this hormone alone may be enough to cause an erection, even in the absence of any physical stimulation. As men get older, usually between ages 40 and 50, natural testosterone levels begin to fall. As this level decreases, episodes of NPT may decrease as well.


Brain relaxation
During your waking hours, your body releases hormones to suppress erections. When you're asleep, your body releases less of those hormones. Combine this fact with the other reasons you may experience an erection in your sleep, and NPT becomes more likely.

What's clearer is what doesn't cause morning wood. For example, needing to urinate isn't responsible for morning wood. Some people believe a morning erection keeps them from urinating during their sleep, but this is not true. Morning wood also isn't always a sign of sexual stimulation. In many cases, NPT isn't caused by dreams or thoughts of a sexual nature.

Morning erections
Every morning when you get up, there are probably a few things you do like clockwork: pee, brush your teeth, pour your morning cup of coffee, etc. You also probably have an erection.

Morning wood, a.k.a. the boner you get the first thing you wake up in the morning, a.k.a. nocturnal penile tumescence (say that 10 times fast!), is extremely common. In fact, if you don't get morning wood, it could be a sign that there's something wrong with the plumbing down there.

That's in part why urologists used to diagnose erectile problems by asking men to put a roll of stamps over their flaccid penises before they went to bed. The idea was that if the roll broke in the morning, it was good news because it meant the guy could get an erection overnight, says Tobias Köhler, M.D., M.P.H., an associate professor and residency program director of the urology division at Southern Illinois University's School of Medicine.

While urologists no longer generally use the "stamp test," the presence of nighttime erections still remain an important indicator of how your entire body is functioning. Read on to find out why your morning wood is important to your health—and why it might be time to see a doctor if your mornings come on a little softer.

What Causes Morning Wood?
During the day, your brain releases a chemical called noradrenaline, a hormone that hinders erections. When you sleep, however, your brain releases less of it. This makes nighttime boners more likely to pop up. In fact, Köhler says most healthy men get erections three to five times a night. 

Another potential cause of morning wood? Testosterone. Even if you're not a morning person, your testosterone levels will likely be the highest in the A.M., which means that you're more likely to wake up feeling like there's a giant roll of quarters in your boxer briefs.

Morning wood also serves another important function: It keeps your penis in fighting shape for when it needs to stand at attention in the bedroom. Frequent erections — say, multiple times a night — keep your penile tissue soft and stretchy, Köhler explains. This prompts the smooth muscle in your penis to relax, which allows the blood to rush in and get you hard.

It's important this happens often because the stretchiness of your penis decreases if the smooth muscles stay contracted for too long, Köhler says. Translation: without regular boners, the length of your erect penis might actually get smaller. And no one wants that to happen.


What does having morning wood say about your health?
Of course, it's impossible for you to know whether or not you're getting boners throughout the night. But if you wake up with morning wood, that typically means there's been healthy blood flow to your penis throughout the night.

If you struggle with erectile dysfunction but you wake up with morning wood, that means the cause of your performance issues is likely psychological and not organic. Stress, anxiety, and depression have been linked to erectile dysfunction, says Köhler, so it may be a good idea to see a therapist. 

But if you have trouble maintaining an erection during sex and you haven't been waking up with morning wood either, blood flow to your penis may be an issue. This is a common symptom of underlying conditions like heart disease, blocked blood vessels, high cholesterol, or high blood pressure.

What to Do If You Don't Get Morning Wood
If you notice a slight decrease in the number of days you wake with morning wood, don't freak out, Köhler says. You might still be experiencing erections during the night, and just not wake up during one.

But if you wake up without a morning erection for several months, you should see a doctor. A complete loss of morning wood can signal underlying health issues like heart disease. It's also one of the first signs of low testosterone.

Treating the underlying issues—say, with statins to clear out cholesterol-clogged veins, or testosterone replacement therapy for guys whose levels tested low — can improve your erections and your overall health, says Köhler.