Genital retraction syndrome (GRS), generally considered a culture-specific syndrome, is a condition in which an individual is overcome with the belief that his/her external genitals or also, in females,
breasts, are retracting into the body, shrinking, or in some male cases,
may be imminently removed or disappear. A
penis panic is sometimes a mass hysteria event or panic where males in a population suddenly exhibit symptoms of genital retraction syndrome.
Penis panics have occurred around the
world, most notably in Africa and Asia. Local beliefs in many instances assert that such syndromes are often fatal. Genital retraction syndrome in Southeast Asia is known as Koro (Malaysian/Indonesian) or
Shook yang (suo yang) in
Chinese cultures. Psychological diagnosis and treatments are under development. It is becoming increasingly clear that these forms of mass hysteria are more common than previously thought.
The phenomenon is often, but not always, associated with occult belief, such as witchcraft. These panics frequently, but not exclusively, occur in places where access to education—particularly in science and human biology—is limited, or otherwise restricted (for example, when
government policies restrict such education). Others have been reported under the influence of drug use. (Compare with castration anxiety.)
