Nocturnal penile tumescence

Last updated

Nocturnal penile tumescence (NPT) is a spontaneous erection of the penis during sleep or when waking up. Along with nocturnal clitoral tumescence, it is also known as sleep-related erection. Colloquially, the term morning wood, or less commonly, morning glory is also used, [1] although this is more commonly used to refer specifically to an erection beginning during sleep and persisting into the period just after waking. Men without physiological erectile dysfunction or severe depression [2] experience nocturnal penile tumescence, usually three to five times during a period of sleep, typically during rapid eye movement sleep. [3] Nocturnal penile tumescence is believed to contribute to penile health. [4]

Contents

Mechanism

The cause of nocturnal penile tumescence is not known with certainty. In a wakeful state, in the presence of mechanical stimulation with or without an arousal, erection is initiated by the parasympathetic division of the autonomic nervous system with minimal input from the central nervous system. [5] Parasympathetic branches extend from the sacral plexus of the spinal nerves into the arteries supplying the erectile tissue; upon stimulation, these nerve branches release acetylcholine, which in turn causes release of nitric oxide from endothelial cells in the trabecular arteries, that eventually causes tumescence. Bancroft (2005) hypothesizes that the noradrenergic neurons of the locus ceruleus in the brain are perpetually inhibitory to penile erection, and that the cessation of their discharge that occurs during rapid eye movement sleep may allow testosterone-related excitatory actions to manifest as nocturnal penile tumescence. [6] Suh et al. (2003) recognizes that in particular the spinal regulation of the cervical cord is critical for nocturnal erectile activity. [7]

The nerves that control one's ability to have a reflex erection are located in the sacral nerves (S2-S4) of the spinal cord. [8] Evidence supporting the possibility that a full bladder can stimulate an erection has existed for some time and is characterized as a 'reflex erection'. [9] A full bladder is known to mildly stimulate nerves in the same region. The possibility of a full bladder causing an erection, especially during sleep, is perhaps further supported by the beneficial physiological effect of an erection inhibiting urination, thereby helping to avoid nocturnal enuresis [ citation needed ]. However, given females have a similar phenomenon called nocturnal clitoral tumescence, prevention of nocturnal enuresis (bed-wetting) is not likely a sole supporting cause. [10]

In a study published in 1972, [11] during puberty, the average tumescence time per night was 159 min; average REM sleep time was 137 min. Average simultaneous REM sleep and penile tumescence per night was 102 min. Study subjects averaged 6.85 tumescence episodes/night, and, of these, 5.15 occurred during a REM sleep period. Tumescence episodes during REM averaged 30.8 min in duration, whereas episodes which occurred when no REM was present averaged 11.75 min. Study subjects had at least four REM periods per night and at least three tumescence episodes.

In another study of healthy older people published in 1988, frequency and duration of nocturnal penile tumescence decreased progressively with age independent of variations in sleep. In contrast to younger age groups, the majority of those above age 60 did not have full sleep erections even though they and their partners reported regular intercourse. [12]

Unlike physiological penile tumescence, sleep-related painful erections (SRPE) and stuttering priapism (SP) are much rarer pathological erections, resulting in poor sleep and daytime tiredness, and long term cardiovascular morbidity. [13] SRPE is a rare parasomnia consisting of nocturnal penile tumescence accompanied by pain that awakens the individual. [14] It occurs predominantly during REM sleep, without an apparent underlying illness or penile anatomic abnormalities. On the contrary, stuttering priapism can occur spontaneously at any time of the day, but more commonly so during REM sleep. SP is a subtype of ischemic priapism that is characterized by recurrent, self-limiting, painful erections that often require maneuvers (compression, cold packs or a cold shower, voiding, or exercise, etc.) to aid detumescence. In ischemic priapism, most of the penis is hard; however, the glans penis is not. Much rarer priapism is secondary to blunt trauma to the perineum or penis, with laceration of the cavernous artery, which can generate an arterial-lacunar fistula resulting in a high blood flow state, hence the tumescence. Tumescence lasting for more than four hours is a medical emergency. [15] At the time being, no treatment consensus for SRPE has been established. Baclofen tablets taken before sleep is the most commonly used medication, having a tolerable profile of adverse effects. [14]

Diagnostic value

The existence and predictability of nocturnal tumescence is used by sexual health practitioners to ascertain whether a given case of erectile dysfunction is psychological or physiological in origin. [3] A patient presenting with erectile dysfunction is fitted with an elastic device to wear around his penis during sleep; the device detects changes in girth and relays the information to a computer for later analysis. If nocturnal tumescence is detected, then the erectile dysfunction is presumed to be due to a psychosomatic illness such as sexual anxiety; if not, then it is presumed to be due to a physiological cause. [3]

Nocturnal penile tumescence testing

Regularly, those who experience erectile dysfunction are given a nocturnal penile tumescence test, usually over a three-day period. Such a test detects the presence of an erection occurring during sleep using either:

  1. a small portable computer connected to two bands placed around the shaft of the penis which records penile tumescence,
  2. a band of paper tape with perforations (similar to coil postage stamps) that is fit snugly around the shaft of the penis and will break at the perforations during penile tumescence.

The goal of nocturnal penile tumescence testing is to determine whether one can experience an erection while sleeping after reporting that they are unable to experience an erection while awake. On average, one has 3–5 episodes of NPT each night, and each episode lasts 30–60 minutes, although the duration is reduced with advanced age. [16] If one does obtain an erection while sleeping, but cannot obtain one while awake, a psychological cause or a medication side effect is usually suspected. Otherwise, if one does not obtain an erection in either state, a physiological cause is usually suspected.

See also

Related Research Articles

Erectile dysfunction (ED), also referred to as impotence, is a form of sexual dysfunction in males characterized by the persistent or recurring inability to achieve or maintain a penile erection with sufficient rigidity and duration for satisfactory sexual activity. It is the most common sexual problem in males and can cause psychological distress due to its impact on self-image and sexual relationships.

<span class="mw-page-title-main">Priapism</span> Medical condition where an erection lasts excessively long

Priapism is a condition in which a penis remains erect for hours in the absence of stimulation or after stimulation has ended. There are three types: ischemic (low-flow), nonischemic (high-flow), and recurrent ischemic (intermittent). Most cases are ischemic. Ischemic priapism is generally painful while nonischemic priapism is not. In ischemic priapism, most of the penis is hard; however, the glans penis is not. In nonischemic priapism, the entire penis is only somewhat hard. Very rarely, clitoral priapism occurs in women.

<span class="mw-page-title-main">Cock ring</span> Sexual device

A cock ring is a ring worn around the penis, usually at the base. The primary purpose of wearing a cock ring is to restrict the flow of blood from the erect penis to produce a stronger erection or to maintain an erection for a longer period of time. They are sometimes used as medical devices, on their own or in conjunction with a penis pump to assist in the management of erectile dysfunction. Genital adornment is another purpose, as is repositioning the genitals to provide an enhanced appearance.

<span class="mw-page-title-main">Penis enlargement</span> Technique aimed to increase the size of a human penis

Penis enlargement, or male enhancement, is any technique aimed to increase the size of a human penis. Some methods aim to increase total length, others the shaft's girth, and yet others the glans size. Techniques include surgery, supplements, ointments, patches, and physical methods like pumping, jelqing, and traction.

Erectile tissue is tissue in the body with numerous vascular spaces, or cavernous tissue, that may become engorged with blood. However, tissue that is devoid of or otherwise lacking erectile tissue may also be described as engorging with blood, often with regard to sexual arousal.

Penile plethysmography (PPG) or phallometry is a measurement of blood flow to the penis, typically used as a proxy for measurement of sexual arousal. The most commonly reported methods of conducting penile plethysmography involves the measurement of the circumference of the penis with a mercury-in-rubber or electromechanical strain gauge, or the volume of the penis with an airtight cylinder and inflatable cuff at the base of the penis. Corpora cavernosa nerve penile plethysmographs measure changes in response to inter-operative electric stimulation during surgery. The volumetric procedure was invented by Kurt Freund and is considered to be particularly sensitive at low arousal levels. The easier to use circumferential measures are more widely used, however, and more common in studies using erotic film stimuli. A corresponding device in women is the vaginal photoplethysmograph.

Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction as a "person's inability to participate in a sexual relationship as they would wish". This definition is broad and is subject to many interpretations. A diagnosis of sexual dysfunction under the DSM-5 requires a person to feel extreme distress and interpersonal strain for a minimum of six months. Sexual dysfunction can have a profound impact on an individual's perceived quality of sexual life. The term sexual disorder may not only refer to physical sexual dysfunction, but to paraphilias as well; this is sometimes termed disorder of sexual preference.

Tumescence is the quality or state of being tumescent or swollen. Tumescence usually refers to the normal engorgement with blood of the erectile tissues, marking sexual excitation, and possible readiness for sexual activity. The tumescent sexual organ in males is the penis and in females is the clitoris and other parts of the genitalia like the vestibular bulbs. Arteries in the penis dilate to increase blood volume.

Anejaculation is the pathological inability to ejaculate despite an erection in males, with (orgasmic) or without (anorgasmic) orgasm.

The cavernous nerves are post-ganglionic parasympathetic nerves that facilitate penile erection and clitoral erection. They arise from cell bodies in the inferior hypogastric plexus where they receive the pre-ganglionic pelvic splanchnic nerves (S2-S4).

<span class="mw-page-title-main">Penile implant</span> Medical device

A penile implant is an implanted device intended for the treatment of erectile dysfunction, Peyronie's disease, ischemic priapism, deformity and any traumatic injury of the penis, and for phalloplasty or metoidioplasty, including in gender-affirming surgery. Men also opt for penile implants for aesthetic purposes. Men's satisfaction and sexual function is influenced by discomfort over genital size which leads to seek surgical and non-surgical solutions for penis alteration. Although there are many distinct types of implants, most fall into one of two categories: malleable and inflatable transplants.

<span class="mw-page-title-main">Human penis</span> Human male external reproductive organ

In human anatomy, the penis is an external male sex organ that additionally serves as the urinary duct. The main parts are the root, body, the epithelium of the penis including the shaft skin, and the foreskin covering the glans. The body of the penis is made up of three columns of tissue: two corpora cavernosa on the dorsal side and corpus spongiosum between them on the ventral side. The urethra passes through the prostate gland, where it is joined by the ejaculatory duct, and then through the penis. The urethra goes across the corpus spongiosum and ends at the tip of the glans as the opening, the urinary meatus. It is a passage both for excretion of urine and the ejaculation of semen.

<span class="mw-page-title-main">Erection</span> Physiological phenomenon involving the hardening and enlargement of the penis

An erection is a physiological phenomenon in which the penis becomes firm, engorged, and enlarged. Penile erection is the result of a complex interaction of psychological, neural, vascular, and endocrine factors, and is often associated with sexual arousal, sexual attraction or libido, although erections can also be spontaneous. The shape, angle, and direction of an erection vary considerably between humans.

<span class="mw-page-title-main">Clitoral erection</span> Physiological phenomenon involving the engorgement of the clitoris

Clitoral erection is a physiological phenomenon where the clitoris becomes enlarged and firm.

Nocturnal clitoral tumescence (NCT), colloquially known as morning bean, is a spontaneous swelling of the clitoris during sleep or when waking up. Similar to the process in males, nocturnal penile tumescence, females experience clitoris tumescence and engorgement of the vagina mainly during the REM sleep phase.

<span class="mw-page-title-main">Sexuality after spinal cord injury</span> Aspect of human sexuality

Although spinal cord injury (SCI) often causes sexual dysfunction, many people with SCI are able to have satisfying sex lives. Physical limitations acquired from SCI affect sexual function and sexuality in broader areas, which in turn has important effects on quality of life. Damage to the spinal cord impairs its ability to transmit messages between the brain and parts of the body below the level of the lesion. This results in lost or reduced sensation and muscle motion, and affects orgasm, erection, ejaculation, and vaginal lubrication. More indirect causes of sexual dysfunction include pain, weakness, and side effects of medications. Psycho-social causes include depression and altered self-image. Many people with SCI have satisfying sex lives, and many experience sexual arousal and orgasm. People with SCI may employ a variety of adaptations to help carry on their sex lives healthily, by focusing on different areas of the body and types of sexual acts. Neural plasticity may account for increases in sensitivity in parts of the body that have not lost sensation, so people often find newly sensitive erotic areas of the skin in erogenous zones or near borders between areas of preserved and lost sensation.

A penile injury is a medical emergency that afflicts the penis. Common injuries include fracture, avulsion injury, strangulation, entrapment, and amputation.

Penile ulltrasonography is medical ultrasonography of the penis. Ultrasound is an excellent method for the study of the penis, such as indicated in trauma, priapism, erectile dysfunction or suspected Peyronie's disease.

Penile implants may be employed to treat erectile dysfunction or urinary troubles after a spinal cord injury.

<span class="mw-page-title-main">Glans insufficiency syndrome</span> Medical condition

Glans insufficiency syndrome, also known as the soft glans, cold glans, or glans insufficiency, is a medical condition that affects male individuals. This condition is characterized by the persistent inability of the glans penis to achieve and maintain an erect or turgid state during sexual arousal, remaining soft and cold. This condition can have an impact on a person's sexual function, including decreased sensitivity, difficulty in maintaining an erection, and overall quality of life.

References

  1. ↑ Schmidt MH, Schmidt HS (March 2004). "Sleep-related erections: neural mechanisms and clinical significance". Current Neurology and Neuroscience Reports. 4 (2): 170–178. doi:10.1007/s11910-004-0033-5. PMID   14984691. S2CID   26939007.
  2. ↑ Thase ME, Reynolds CF, Jennings JR, Frank E, Howell JR, Houck PR, et al. (May 1988). "Nocturnal penile tumescence is diminished in depressed men". Biological Psychiatry. 24 (1): 33–46. doi:10.1016/0006-3223(88)90119-9. PMID   3370276. S2CID   24315629.
  3. 1 2 3 Felson S (7 November 2020). "Tests for Erection Problems". WebMD, Inc. Retrieved 2007-03-03.
  4. ↑ Alexander B (October 2010). "Why guys rise and, well, rise in the morning?". The Body Odd. NBC News.
  5. ↑ "SCI Fact Sheets - Spinal Cord Injury Model System". Heersink School of Medicine. The University of Alabama at Birmingham (UAB).
  6. ↑ Bancroft J (September 2005). "The endocrinology of sexual arousal". The Journal of Endocrinology. 186 (3): 411–427. doi: 10.1677/joe.1.06233 . PMID   16135662.
  7. ↑ Suh DD, Yang CC, Clowers DE (January 2003). "Nocturnal penile tumescence and effects of complete spinal cord injury: possible physiologic mechanisms". Urology. 61 (1): 184–189. doi: 10.1016/S0090-4295(02)02112-X . PMID   12559293.
  8. ↑ Klebine P, Lindsey L (May 2007). "Sexual Function for Men with Spinal Cord Injury". Spinal Cord Injury Information Network. University of Alabama at Birmingham. Archived from the original on 2013-09-06. Retrieved 2011-12-17.
  9. ↑ "Nervous system control of the male reproductive system". Spinal Hub. Retrieved 2018-01-09.
  10. ↑ Beale S (Aug 2016). "Why Do Men Get Erections in the Morning". IFL Science. Retrieved 2016-12-03.
  11. ↑ Karacan I, Hursch CJ, Williams RL, Littell RC (June 1972). "Some characteristics of nocturnal penile tumescence during puberty". Pediatric Research. 6 (6): 529–537. doi: 10.1203/00006450-197206000-00001 . PMID   4340042. S2CID   10758883.
  12. ↑ Schiavi RC, Schreiner-Engel P (September 1988). "Nocturnal penile tumescence in healthy aging men". Journal of Gerontology. 43 (5): M146–M150. doi:10.1093/geronj/43.5.m146. PMID   3418036.
  13. ↑ Johnson M, McNeillis V, Gutbier J, Eaton A, Royston R, Johnson T, et al. (September 2022). "Differences in polysomnographic, nocturnal penile tumescence and penile doppler ultrasound findings in men with stuttering priapism and sleep-related painful erections". International Journal of Impotence Research. 34 (6): 603–609. doi:10.1038/s41443-021-00462-3. PMC   9485052 . PMID   34389802. S2CID   236993535.
  14. 1 2 Abdessater M, Kanbar A, Zugail AS, Al Hammadi A, Guillonneau B, Beley S (December 2019). "Sleep related painful erection: an algorithm for evaluation and management". Basic and Clinical Andrology. 29 (1): 15. doi: 10.1186/s12610-019-0095-5 . PMC   6894200 . PMID   31844522.
  15. ↑ Podolej GS, Babcock C (January 2017). "Emergency Department Management Of Priapism". Emergency Medicine Practice. 19 (1): 1–16. PMID   28027457.
  16. ↑ Bella AJ, Lue TF (12 December 2007). "Male Sexual Dysfunction". In Tanagho EA, McAninch JW (eds.). Smith's General Urology (17th ed.). McGraw Hill Professional. pp. 589–. ISBN   978-0-07-159331-1.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.