Koro: Living in Fear of a Small Penis

Let’s face it: given a choice, most men would opt to be granted a humongous penis, even knowing full well that penis size does not have anywhere near the effect on sexual satisfaction that penis skill and penis health do. Most men, especially given society’s emphasis on the subject, can’t help but equate a big penis with virility and sexual appeal and a small penis with… well, not femininity, but certainly not with impressive sexual conquests. Fear of possessing a small penis can be compounded when a man develops koro, a condition in which he believes that his penis may actually be shrinking or in danger of shrinking.


Also known as genital retraction syndrome (GRS), koro describes a condition in which a person has an overwhelming, almost unshakeable belief that their genitals are shrinking, possibly to the point of actually disappearing from view. (In women, it may manifest as a belief that the breasts are shrinking). Sometimes the fear is not that the penis is shrinking but that it is in danger of being removed, either through castration or some other, often supernatural means.

Koro is a Malaysian term (meaning “head of the turtle”) that was first used in the 16th century. However, the concept of a belief that the penis is shrinking is much older and has appeared in many different cultures. It also is not something relegated to ancient beliefs or naïve people. Instances of koro have been documented in Europe, Africa and the United States in more modern times.

Sometimes koro can seem to “take hold” of a region during a period of time, resulting in significant numbers of men believing a small penis is in their future. This becomes a “penis panic,” with mass numbers of males fearing for their penises.

Psychological issue

Koro is considered a psychological issue and is included in the Diagnostic and Statistical Manual of Mental Disorders. That means if a man actually has a penis which is shrinking, he most likely does not have koro; if, however, if he has delusions of a shrinking penis or irrational fears that a small penis is in his future and no physical reasons for this fear, he is classified as afflicted by koro.

In some cases, the anxiety related to koro can be very high, bringing about feelings of panic, stress, worry, anger and other emotions. These can manifest in physical issues, including depression, loss of sleep, fatigue, etc. Some men believe the perceived penis shrinkage will end in their deaths, which can create possible suicidal or violent tendencies.

The cause of koro can vary. It may result from a belief in the supernatural, for instance, or it can come about because a man (or a group of men) feel disempowered by the society or culture in which they live. Sometimes guilt may come into play, especially if a man has been brought up to be ashamed of sexual feelings or masturbation.


If a man has a fear that his penis is shrinking, he should first consult a doctor to rule out any possible physical reasons why actual shrinkage might be occurring (e.g., Peyronie’s disease, obesity causing part of the penis to be hidden beneath fat, etc.). If there is no physical reason, he should consult with a mental health professional who can help devise strategies to address his small penis anxiety.

Koro: Living in Fear of a Small Penis was last modified: by
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