Morning erections happen during REM sleep and are normal, reflecting healthy circulation and hormones.
Why
Nocturnal erections happen 3 to 5 times a night during REM sleep. Waking up during one gives you “morning wood”.
Causes
- Rise in testosterone in the morning.
- REM sleep activity.
- Reduced norepinephrine, which lets blood flow.
Is it healthy
Yes. It shows healthy circulation and nerve function.
See a doctor
If you stop having them, as it may signal a health issue.
Nocturnal erections
Erections during sleep are known as nocturnal penile tumescence. Healthy males usually have 3 to 5 erections per night, each lasting about 25 to 35 minutes, during REM sleep. They occur from infancy, even in the womb, through adulthood.
Why they happen
During REM sleep, the brain stem reduces activity of the sympathetic nervous system, which normally keeps the penis flaccid, and the parasympathetic system becomes more active, increasing blood flow. Testosterone levels also play a role, with peak levels in the morning.
Not necessarily sexual
Morning erections are not caused by sexual dreams or a full bladder. A full bladder can sometimes prolong them.
Health significance
Regular nocturnal erections indicate that blood vessels, nerves and hormones are working well. Their absence in a man with erectile problems can suggest a physical rather than psychological cause.
Changes with age
They become less frequent with age, but they continue into older age. A study of Swedish men found frequency declining through adulthood.
Causes of fewer erections
- Low testosterone.
- Diabetes.
- Cardiovascular disease.
- Sleep apnea.
- Medications, including antidepressants and blood pressure drugs.
- Alcohol, smoking and drugs.
- Depression and stress.
Normal for males
It is considered a sign of normal function and no treatment is needed.
See a doctor if
Erections stop entirely along with difficulty during sex, low desire, or you have painful or prolonged erections lasting more than 4 hours (priapism), which is an emergency.
Physiology of nocturnal erections
Nocturnal penile tumescence is a normal part of sleep that occurs mostly during REM sleep, about three to five times a night, each lasting 25 to 35 minutes. It is driven by changes in the autonomic nervous system, where parasympathetic activity rises, and by nitric oxide release, increasing blood flow. It is not necessarily linked to sexual dreams or arousal. Waking up with an erection is common in boys and men and generally becomes less frequent with age.
Health significance
Doctors sometimes ask about morning erections when evaluating erectile dysfunction, because their presence suggests blood vessels and nerves are working. Their absence can be linked to low testosterone, diabetes, cardiovascular disease, sleep apnea, medications, depression or stress. Erectile dysfunction affects an estimated 30 million men in the US, according to the NIDDK. See a doctor if a sustained change occurs, particularly with other symptoms such as low desire or fatigue. Healthy habits such as exercise, quality sleep and avoiding smoking support erectile function.
Based on data from the NIDDK and the Urology Care Foundation
