“Vanishing Penis” Syndrome: What, Why and How to Manage It

Andrew Siegel MD   5/9/2020

Vanishing Penis Syndrome is an affliction that refers to one’s penis shrinking or retracting, a not uncommon complaint voiced by patients seeking urology consultation.  In distinction from the actual physical occurrence of this, there also exists a purely psychological form of this ailment that is a type of body dysmorphic disorder.  This psychological disorder is known as genital retraction syndrome, a.k.a. Koro, the fear of one’s penis shrinking and retracting within the body, without it actually occurring physically.

Those who encounter diminished dimensions of their manhood, whether real or imagined, are typically unhappy campers.  Penile retraction not only negatively affects sexuality, but also one’s ability to effectively urinate in the standing up position. The combination of a vanishing and increasingly internalized penis as well as the need to sit to urinate can be physically and psychologically emasculating.


Image above: Roman copy of Apollo Delphinios by Demetrius Miletus at the end of the second century (Attribution: Joanbanjo (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)%5D, via Wikimedia Commons)

Today’s entry refers to a genuine decrease in penile length and girth in both flaccid and erect states and not to the temporary contraction in penis size that normally accompanies exposure to cold (remember the George Costanza scene in Seinfeld…”I was in the pool, I was in the pool!”), flight-or-fight response situations that decrease blood flow to the organ via release of adrenaline (a hormone that constricts blood flow), and athletic endeavors that may shunt blood from the pelvis to oxygenate the muscles in demand (“stealing from Peter to pay Paul”).

Q. Is shrinkage for real?

A. Yes, it is often a genuine finding, but at times it is a matter of perception with the penis hiding, usually behind a pubic fat pad (One of my patients describes this as “turtle dick”).

Q. Does it inevitably happen to everyone as they get older?

A. No.

Q. What can be done about it?

A. Read on.

Penile Anatomy and Function 101 (super-abbreviated)

The penis has a hidden internal component that is anchored to the pubic bone in addition to the obvious external component. The inner penis is analogous to the roots of a tree that provide stability and foundational support. The penis consists of paired erectile chambers (corpora cavernosa) that run the length of the penis and a solitary spongy chamber (corpus spongiosum) that surrounds the urinary channel and extends to form the head of the penis (see image below). The erectile chambers are composed of sinus tissue and are surrounded by a tough outer sheath. When the penile blood supply, nerves, and sinus tissue are functioning properly, sexual stimulation will cause blood to gush into the 3 erectile chambers, expanding the length and girth of the penis, giving rise to a firm penis (tumescence).

Screen Shot 2020-02-03 at 5.19.57 PM

Erectile chambers of the penis, from Male Pelvic Fitness

Maximum erectile rigidity only occurs after engagement of the ischiocavernosus (IC) and bulbocavernosus (BC) pelvic floor muscles that surround and compress the inner penis, forcing and trap pressurized blood into the external penis (see illustration below).


The pelvic floor erectile rigidity muscles–IC and BC– that surround the inner penis, from Male Pelvic Fitness


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Cross section of the penis, from Male Pelvic Fitness

5 Reasons Why One Might Be “Half The Man You Used To Be”

  1. Erectile dysfunction (ED) with consequent sexual inactivity
  2. Weight gain
  3. Low testosterone
  4. Radical prostatectomy
  5. Peyronie’s disease

Erectile dysfunction: Use It or Lose It

“Disuse atrophy” can affect all bodily structures, including the penis. In the absence of erections and with the disappearance of sleep-time erections that function to keep the penis well oxygenated, the erectile tissues can  undergo decompensation and atrophy. In a vicious cycle, the poor blood flow resulting from disuse produces a state of poor oxygen levels in the penile smooth muscle and erectile tissues that, in turn, can induce scarring, resulting in a loss of penile length and girth and further negatively affecting one’s ability to achieve an erection.

With erections and sexual activity, a surge of blood flow to the penis occurs and the hydraulic expansion of the erectile chambers keeps the penile tissues richly oxygenated, elastic, supple, healthy and functioning.

Sexual intercourse on a regular basis protects against erectile dysfunction (ED).  The risk of ED is inversely related to the frequency of intercourse. Men reporting intercourse less than once weekly have twice the incidence of ED as compared to men reporting intercourse once weekly.

Weight gain: As Your Pannus Gets Bigger, Your Penis Gets Smaller

Weight gain and obesity cause the fatty tissue above the pubic bone to become more ample, the male equivalent of the female mons pubis, the rounded mound of fat overlying the pubis. In addition to this fatty mound that can obscure the penis, weight gain can create a “pannus,” literally an apron of abdominal fat that hangs with gravity. The combination of a pubic fat pad and a pannus will make the penis appear shorter as it is obscured within the mass of fatty tissue.  The truth of the matter is that penile length is usually intact, with the penis merely hiding behind the fat.  Lose the fat and the penis will reappear.

Note well: It is estimated that for every 35 lbs. of weight gain, there is a one-inch loss in apparent penile length…Yet another reason to stay lean!

Low testosterone: Not Enough Male Rocket Fuel

Testosterone is a sex hormone that plays a pivotal role in maintaining penile erectile tissue architecture and function.  Low levels can adversely affect penile dimensions and this is particularly the case with markedly diminished levels, as seen with androgen deprivation therapy, a means of suppressing testosterone, used as a form of treatment for prostate cancer. Low testosterone can be caused by testes failure from undescended testes, twisted testes, testes infections, testes removal, Klinefelter’s syndrome, chemotherapy and toxic damage from alcohol or heavy metals.  It can also be caused by pituitary-hypothalamic issues including injury from tumor, trauma or radiation. Medications that decrease testosterone levels include ketoconazole, opioid pain relievers, many anti-depressants including SSRIs and SNRIs and excessive alcohol.

Radical prostatectomy

Surgery to remove the prostate as a treatment for prostate cancer can result in penile shortening on the basis of several factors. The prostate gland with enclosed prostatic urethra is excised with the subsequent gap in the urethra bridged by sewing bladder neck to urethral stump, with a consequent loss of urethral length that can create a “telescoping” phenomenon with shortening. Furthermore, traumatized and impaired nerves and blood vessels vital for erections can give rise to ED, with the lack of regular erections resulting in less oxygen delivery to penile smooth muscle and elastic fibers causing scarring, shortening and narrowing of the penile tissue as discussed above under the heading of disuse atrophy.  Moreover, Peyronie’s disease can sometimes result as a consequence of prostatectomy, further compounding the shortening.

Resuming sexual activity as soon as possible after surgery will help “rehabilitate” the penis and prevent disuse atrophy. There are a variety of effective penile rehabilitation methods to achieve this endpoint, to be reviewed in a future entry.

Peyronie’s disease: The Curve You Don’t Want

Named after the French surgeon de la Peyronie who first described it in 1743, Peyronie’s disease is an acquired deformity of the penis that occurs due to scarring of the sheath surrounding the erectile chambers. It can result in a hard lump, penile shortening and narrowing, curvature with erections, a visual indentation that can be described as an “hour-glass” deformity, pain with erections and ED.  Penile pain, curvature and poor expansion of the erectile chambers contribute to difficulty in having a functional and anatomically correct rigid erection suitable for intercourse. The penile shortening occurs because scarring of the erectile cylinders prevents them from expanding properly.

5 Ways to Maintain Penile Health and Avoid Being “Short-staffed”

  1. Healthy lifestyle: wholesome nutrition, weight management, exercise including pelvic floor muscle training, tobacco cessation, moderate alcohol intake, stress management
  2. Trim down: lose the pannus and regain the penis
  3. Stay sexually active: use it or lose it
  4. Testosterone replacement: when one has symptoms of low testosterone and lab  confirmation of low levels
  5. For shortening/erectile issues after prostate surgery or from Peyronie’s: oral medications, traction therapy, vacuum suction therapy, injection therapy, etc.  Check in with your urologist for more information on these options.

Wishing you the best of health,

2014-04-23 20:16:29

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Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery.  He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro Area, Inside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community. He is a urologist at New Jersey Urology, the largest urology practice in the United States.  His latest book is Prostate Cancer 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families. 

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Video trailer for Prostate Cancer 20/20

Preview of Prostate Cancer 20/20

Andrew Siegel MD Amazon author page

Prostate Cancer 20/20 on Apple iBooks

PROSTATE CANCER 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families is now on sale at Audible, iTunes and Amazon as an audiobook read by the author (just over 6 hours). 

Dr. Siegel’s other books:

FINDING YOUR OWN FOUNTAIN OF YOUTH: The Essential Guide to Maximizing Health, Wellness, Fitness and Longevity

PROMISCUOUS EATING— Understanding and Ending Our Self-Destructive Relationship with Food

MALE PELVIC FITNESS: Optimizing Sexual and Urinary Health

THE KEGEL FIX: Recharging Female Pelvic, Sexual, and Urinary Health




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