Sleeping Men
Wu Binbin (bottom) and Chen Huiyang, employees at BaishanCloud, take a nap after lunch in individual sleeping quarters, in the office, in Beijing, China. Reuters/Jason Lee

Given the chance, most men would likely want to be like the burying beetle when it comes to erections since the insect’s genital grows longer over time and has bigger erection due to frequent sex. But in the case of humans, as they age, even having morning erections is no longer true all the time.

Men should not be ashamed when they wake up and their genitals are rock hard because a morning erection is a sign of good cardiovascular health, says Dr David Samadi, a urologist. The professor of urology at Hofstra North Shore-LIJ School of Medicine, in a column in The New York Daily News, writes that the boner is a sign of vigorous blood levels of testosterone, a reflection of overall good health.

Samadi explains that men experience morning erections because the brain releases the hormone noradrenaline at daytime which averts having uninvited, unintended and often embarrassing spontaneous daytime erections. At night, the brain releases less of the hormone, resulting in involuntary erections.

He estimates that a healthy male has three to five erections while sleeping at night which lasts between 25 and 35 minutes each. Called nocturnal penile tumescence (NPT), the last of the nighttime erections is the morning boner.

The urology expert cites theories that link NPT to the sleep cycle. The penis normally begins to arouse when the body shifts into a rapid eye movement cycle and ends when the man transitions into deeper sleep.

He adds that it is not only sexually mature men who experience a hard on in the morning but even baby boys in utero and among male animals. In some cases, the full bladder also contributes to a morning erection. Those taking Cialis, an erectile dysfunction drug, could also notice more morning erection due to the lingering effect of the active ingredient of tadalafil.

In 2013, Dr Debby Hebernic, co-director of the Center for Sexual Health Promotion at Indiana University’s School of Public Health-Bloomington, found that having oral sex played a part in reporting greater length and circumference of their penises among more than 1,600 American men surveyed using the self-reporting technique.