Imagine a doctor telling you to wear a roll of stamps around your penis to bed. You would probably find a new doctor. But several decades ago, urologists used the technique to test men for erectile problems.
If the perforations were torn in the morning, that was good news: It meant the guys popped 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 medical testing has grown more sophisticated and 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.
In fact, a healthy man should expect to get hard three to five times per night, says Dr. Köhler.
Obviously you won’t know what happens after you go to bed. But if you’re not waking up with an erection on occasion, it’s time to see a doctor.
Why Morning Wood Occurs
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 those nighttime boners more likely to pop up.
They happen sporadically throughout the night, so whether you wake up with one or not is just up to chance.
What Morning Wood Says About Your Health
Consistently having erections while you sleep indicates healthy blood flow to your penis, which is also necessary for getting hard when you’re turned on.
So if you experience erection problems when you’re trying to get busy—but you pop them overnight or when you wake up in the morning—that points more to a psychological cause of your ED, like performance anxiety or depression, says Dr. Köhler.
But if you haven’t been experiencing erections at night either, that signals that blood flow to your penis may be an issue. This is a common characteristic of underlying conditions like heart disease, blocked blood vessels, high cholesterol, or high blood pressure.
How Nighttime Erections Benefit Your Penis
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.
“Your penis is a ‘use it or lose it’ organ,” says Dr. Köhler.
Frequent erections—say, multiple times a night—keep your penile tissue soft and stretchy, Dr. Köhler explains.
They also prompt 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, Dr. Köhler says. Without a regular relaxing-contracting workout, the length of your erect penis may actually shorten.
What To Do If You Don’t Get Morning Wood
Don’t worry if you notice a slight decrease in the number of days you wake with morning wood, Dr. Köhler says. You might still be experiencing erections during the night, and just not waking up during one.
But see your doctor if you wake up without a morning erection for several months. A complete loss of them can signal depression, chronic stress, or 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 often improve your erections, says Dr. Köhler.