What Causes Morning Wood?

By Brandon Peters, MD Updated on March 23, 2023
Medically reviewed by Jamin Brahmbhatt, MD

This article is a repost which originally appeared on verywell health

Edited for content. The opinions expressed in this article may not reflect the opinions of this site’s editors, staff or members.

Key Points

‧ Morning erections are not necessarily associated with sex dreams.

‧ During sleep, REM sleep cycles affect erectile activity.

‧ Subtle contact of the penis with bedsheets can induce erections.

“Morning wood” is when the penis engorges with blood and you wake up with an erection. This is a perfectly normal occurrence. Most morning erections tend to last for a few minutes after awakening but can persist for longer.

Despite what some think, these erections are not so much associated with “sex dreams” as they are certain parts of the sleep cycle—namely, REM sleep.1 Changes in hormone levels, a full bladder, and even physical stimulation from a bedsheet can also cause morning wood.

This article explains the causes of morning erections, clinically known as nocturnal penile tumescence. It also reviews factors that independently contribute to morning wood in people with penises.

Erections and Your Sleep Cycle

Morning erections correspond to the timing of rapid eye movement (REM) sleep. Because REM sleep effects neurological stimulators that increase blood flow to the penis, penile erection is more likely during this part of the sleep cycle.1

Everybody has different sleep patterns. But since there are usually four or five stages of REM sleep during the night, people with penises may have four or five erections during the night, too. Each erection can last 25 to 35 minutes, though this doesn’t necessarily happen every night.

People stay in REM stage sleep for longer as morning approaches. By the time they wake, they are often still coming out of REM sleep. This is why you may experience morning wood, which typically subsides within a few minutes of awakening.

It seems that the body is doing what healthcare providers refer to as “testing systems” during sleep. This is a normal and healthy phenomenon in people with penises. In fact, it can also happen in those without them: The clitoris can become engorged with blood and erect during REM sleep as well.

Hormones Levels in the Morning

The sex hormone testosterone plays a central role in the sexual functions of people with penises. Research has shown that testosterone helps facilitate nearly every facet of an erection, from the activation of nerves that stimulate smooth muscles of the penis to the engorgement of blood in the spongy interior of the penis.

Testosterone levels also fluctuate and tend to be higher early in the morning than in the afternoon or evening.

This incidental increase can also be one of the contributing factors to a morning erection.

Even Subtle Touch Can Cause Erections

Physical touching of the penis can, on its own, cause an erection in the absence of sexual stimulation. Research has shown that physical stimulation sends sensory signals directly to the lower part of the spinal cord which functions at the body’s “erection center.”

Even when half-asleep or half-awake, these sensory nerves can be alert to even subtle changes in the environment. As such, the tactile sensation of a bedsheet or pajama fabric against the penis may be enough to provoke a morning erection.

Effect of a Full Bladder

Men who don’t get up to urinate during the night will have a full bladder in the morning. A full bladder can press on the sacral nerve, which is a group of five nerves in the lower back.

Your nervous system helps keep your body running while you sleep. Because the sacral nerve is responsible for erections while you’re asleep or half-asleep, stimulation of the nerve from a full bladder can cause an erection.

Morning erections can be a reassuring sign that your nerves, blood supply, and circulation are healthy.

What If Morning Erections Stop or I Never Have Them?

If you do not wake with an erection, it is not necessarily abnormal. It could be that you did not wake from REM sleep. It is also possible that the erection began to fade prior to waking completely.

In general, sleep-related erections decrease with age. But if you’re not waking at least occasionally with an erection, if may be time to visit your healthcare provider for a check-up.

Adolescents, teens, and young adults tend to have morning wood more often than older adults.

A complete lack of morning erections may suggest a problem with the blood vessels or nerves. It can also indicate erectile dysfunction, a common condition in which a person is unable to get or keep an erection firm enough for satisfactory sexual intercourse.

See your healthcare provider. They will probably want to do a full health history and eliminate other possibilities, such as obstructive sleep apnea, which is just one condition that can affect erections. A diagnostic sleep study called a polysomnogram may be recommended.

What If a Morning Erection Doesn’t Go Away?

Persistent erections may occur in a condition called priapism. With this uncommon condition, either blood flow through the penis is not as it should be (nonischemic or high-flow priapism) or blood gets trapped in the penis after it becomes erect (ischemic or low-flow priapism).

Priapism can result in erections that last hours. With nonischemic cases, the shaft of the penis may lose some rigidity and you likely won’t experience pain. With ischemic priapism, the shaft is rigid, the tip is soft, and there is pain that worsens with time.

Give the erection some time to resolve. If it goes away, but long-lasting and/or painful erections keep happening, see your healthcare provider.

If your erection lasts for more than four hours, go to the emergency room.

Summary

Morning erections correspond to the timing of rapid eye movement (REM) sleep, which you may still be coming out of when you wake up. They can also be caused by hormone fluctuations, a full bladder, and subtle touch.

These erections typically resolve within minutes of you waking up.

Morning wood is not only common, but normal. If you don’t ever experience these erections, they stop, or they last several hours, see a healthcare provider.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Youn G. Why do healthy men experience morning erections? Open Psychol J. 2017;10(1). doi:10.2174/1874350101710010049

Isidoria AM, Buvat J, Corona G, et al. A critical analysis of the role of testosterone in erectile function: from pathophysiology to treatment—a systematic review. Eur Urol. 2014 Jan;65(1):99-112. doi:10.1016/j.eururo.2013.08.048

Crawford ED, Poage W, Nyhuis A, et al. Measurement of testosterone: how important is a morning blood draw? Curr Med Res Opin. 2015;31(10):1911-4. doi: 10.1185/03007995.2015.1082994

Boston University School of Medicine. The central mechanisms of sexual function.

Leungwattanakij S. Erectile dysfunction. Bangkok Med J. 2016;11:57-. doi:10.31524/bkkmedj.2016.02.012

Urology Care Foundation. What is Priapism?

 

 

 

 

 

 

 

 

How biohackers use fasting, sleep monitoring, and low-meat diets to ‘turn back’ their biological clock

Ulrike Bartholomäus and Nathan Rennolds , Business Insider Deutschland Feb 1, 2022, 12:48 PM

This article is a repost which originally appeared on BUSINESS INSIDER

Edited for content.

Intermittent fasting may improve blood fat levels, and can lower blood pressure.

‧ Biohacking is a US sports trend. It involves trying to hack your body to look and feel younger.

‧ Intermittent fasting, eating less meat, and HIIT are some of the tools used.

‧ These work to improve blood lipid levels, lower blood pressure, and improve sleep.

The dream of eternal youth is as old as mankind, but it seems some researchers are one step closer to figuring out how to slow the ageing process.

Even 70- to 77-year-olds can lower their mortality with high-intensity interval training (HIIT), a Norwegian study has found.

In the study, researchers at the University of Trondheim compared the exercise activities of 1,567 people, who averaged 72 years of age, over a five-year period. 

Those who completed the HIIT (“high intensity interval training”) program outperformed the other two groups, who did moderate exercise or normal sports at a significantly lower heart rate. 

Biohackers, who follow a trend originating in the US, are using “hacks” to try and “turn back” their biological clocks.

One of the most prominent biohackers is Silicon Valley entrepreneur David Asprey. He weighed around 309 lbs as a 26-year-old because his diet was centered around pizza, chips, and Coca-Cola. His arteries were as old as his grandfather’s. 

“I decided to radically change my life because if I hadn’t, I would have dropped dead soon enough,” recalled Asprey. 

That’s when he started trying everything possible to rejuvenate his body and brain cells. 

“The first thing I do is skip my breakfast and just drink my Bulletproof coffee, which is an organic coffee that has a little ghee mixed in, as well as a little MCT oil,” he explained. 

The clarified butter, which is all ghee is, suppresses the feeling of hunger, as does the caffeine. The MCT oil is based on coconut oil and contains saturated fats called caprylic and capric acids. 

“They help the body create important fasting substances called ketone bodies. They dispose of excess cellular waste during the morning fasting period,” Asprey said. 

Max Gotzler is a well-known German biohacker. His book, “Der tägliche Biohacker” (The Daily Biohacker), published in October, promises to teach you “how to be more efficient, healthier, more resilient, more balanced, and more productive every day in small steps.”

If only it were that simple. 

“Intermittent fasting improves blood fat levels”

Renowned aging researcher David Sinclair of Harvard Medical School, who’s been studying longevity genes for decades, confirmed that skipping breakfast or dinner — intermittent fasting — can rejuvenate us. That’s because the temporary starvation changes our metabolism — instead of sugar, we burn fat, disposing of useless cellular waste. In this cleansing phase, we get rid of inflammatory cells, for example, which can do great damage to our bodies.

“Studies show that intermittent fasting improves blood fat levels, and can lower blood pressure,” said Berlin cardiologist and general practitioner Natascha Hess. 

“Especially when combined with exercise,” she added. 

Fasting rejuvenates blood vessels in 95% of all cases. 

“However, those who have a genetic lipid metabolism disorder are dependent on medication in addition to lifestyle changes,” Hess said. 

So biohacking doesn’t always work.

“Those who don’t sleep enough suffer from more pain”

Biohackers also focus on improving sleep. To do this, they use watches and fitness bands with apps — or wearables — that record sleep phases. A popular example is the Oura Ring.

Using small sensors on the inside, the ring measures sleep phases in a similar way to fitness bracelets. With the help of an app on your smartphone, you can check how many deep sleep and REM sleep phases you have gone through. REM sleep is the time during which we emotionally process the experiences of the day and store them in our memory. 

“If you have too few deep sleep or REM sleep phases, you can only renew your cells insufficiently. You age faster,” said Berlin orthopedist, sports physician, and pain specialist Christopher Topar, who’s been testing the Oura ring for a few months. 

“60% of my pain patients say they sleep badly. Those who don’t sleep enough suffer from more pain,” he said. 

Knowing which apps, smart fitness watches, or wearables his patients can use to improve their sleep is part of his holistic approach. 

In recent years, scientists have discovered how ill lack of sleep can make us. It’s not just daily exhaustion we struggle with; poor sleep increases the risk of heart disease, obesity, and diabetes. Headaches and depression also occur when we sleep too little or too poorly.

Not everyone is going to improve their sleep by wearing a fitness bracelet, watch, or ring to track their sleep stages. 

“However, such gadgets help us find out why we sleep poorly, wake up repeatedly at night, or wake up too early in the morning,” Topar said. 

Some people may have eaten too late, others may be sleeping badly due to too much alcohol or television.

It’s also known that reading on a smartphone or tablet suppresses the release of the hormone melatonin, which the body normally releases in the evening and is supposed to make us tired, due to the blue light that these devices emit. This would also explain why so many children who play games with a computer or tablet until the evening suffer from trouble falling asleep.

Nutrition plays a key role

Another important part of the biohacker lifestyle is nutrition. They advise eating less red and processed meats.

David Sinclair believes your plate should look colorful with yellow, red, or green vegetables rich in phytochemicals called polyphenols. 

“These substances inhibit the growth of inflammatory and cancer cells,” said the Harvard professor.

Biohackers have also been known to use some controversial methods.

David Asprey, for example, had his body’s own stem cells transplanted into other parts of his body, including his sex organs. 

You can read about his biohacks in the book “Super Human: The Bulletproof Plan to Age Backward and Maybe Even Live Forever.” 

This is just as unadvisable as overdoing diet, exercise, and sleep control. 

“Our health should be at the center of our lives, but controlling it should not rule us,” said cardiologist Hess. But she advises a bit of self-measurement using apps for many of her patients. 

“You’re often surprised how many calories are in a ‘small snack’ and that it takes half an hour of exercise to burn them off again.”

Relaxation is another important factor in maintaining a healthy lifestyle, and it’s often overlooked. If we’ve had a particularly stressful day, it’s important to tell our body that it’s allowed to relax in the evening. Doing this should stop the release of the stress hormones adrenaline and cortisol, allowing the body and mind to properly rest.