Nosophobia is the irrational fear of contracting a disease, a type of specific phobia. Primary fears of this kind are fear of contracting HIV, pulmonary tuberculosis, venereal diseases, cancer, and heart diseases.

Some authors have suggested that the medical students' disease should accurately be referred to as "nosophobia" rather than "hypochondriasis", because the quoted studies show a very low percentage of hypochondriacal character of the condition.

The word "nosophobia" comes from the Greek νόσος "nosos" for "disease".

There can be many different reasons for why people develop genophobia. Some of the main causes are former incidents of sexual assaults or abuse. These incidents violate the victim’s trust and take away their sense of right to self-determination. Another possible cause of genophobia is the feeling of intense shame or medical reasons. Others may have the fear without any diagnosable reason.

There is no universal cure for genophobia. Some ways of coping with or treating anxiety issues is to see a psychiatrist, psychologist, or licensed counselor for therapy. Some people experiencing pain during sex may visit their doctor or gynecologist. Medicine may also be prescribed to treat the anxiety brought on by the phobia.

Several criteria are typically used to make a diagnosis of koro. The primary criteria is a patient's report of genital (typically penile or female nipple) retraction despite a lack of objective physical evidence demonstrating retraction. This is accompanied by severe anxiety related to the retraction, fear of death as a result of retraction, and use of mechanical means to prevent retraction. Cases that do not meet all the requirements are generally classified as koro-like symptoms or given a diagnosis of partial koro syndrome. It has been argued that the criteria are sufficient but not necessary to make a diagnosis of koro. Researchers have identified Koro as a possible "cultural relative" of Body Dysmorphic Disorder. DSM-IV explains the process of differential diagnosis between these two disorders.

In historical culture-bound cases, reassurance and talks on sexual anatomy are given. Patients are treated with psychotherapy distributed according to symptoms and to etiologically significant points in the past. Prognosis appears to be better in cases with a previously functional personality, a short history and low frequency of attacks, and a relatively uncomplicated sexual life.

For sporadic Western cases, careful diagnostic workup including searching for underlying sexual conflict is common. The choice of psychotherapeutic treatment is based on the psychiatric pathology found.