Another author, writing about halitosis, noted that there are generally three types of persons that complain of halitosis: those with above-average odor, those with average or near-average odor who are oversensitive, and those with below-average or no odor who believe they have offensive breath. Therefore, in persons with genuine odor complaints, the distress and concern may typically be out of proportion to the reality of the problem. Genuine halitosis has been described as a social barrier between the individual and friends, relatives, partners and colleagues, and may negatively alter self-esteem and quality of life. Similar psychosocial problems are reported in other conditions which cause genuine odor symptoms. In the literature on halitosis, emphasis is frequently placed on multiple consultations to reduce the risk of misdiagnosis, and also asking the individual to have a reliable confidant accompany them to the consultation who can confirm the reality of the reported symptom. ORS patients are unable to provide such confidants as they have no objective odor.Various organic diseases may cause parosmias (distortion of the sense of smell). Also, since smell and taste are intimately linked senses, disorders of gustation (e.g. dysgeusia—taste dysfunction) can present as a complaint related to smell, and vice versa. These conditions, collectively termed chemosensory dysfunctions, are many and varied, and they may trigger a person to complain of an odor than is not present; however, the diagnostic criteria for ORS require the exclusion of any such causes.
It is also suggested to be a type of body dysmorphic disorder or, as it involves a single delusional belief, some suggest that ORS is a monosymptomatic hypochondriacal psychosis (hypochondriacal type of delusional disorder, see monothematic delusion).The World Health Organizations 10th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) does not have a specific entry for ORS, or use the term, but in the "persistent delusional disorders" section, states delusions can "express a conviction that others think that they smell. "ORS has also never been allocated a dedicated entry in any edition of the American Psychiatric Associations Diagnostic and Statistical Manual of Mental Disorders. In the third edition (DSM-III), ORS was mentioned under "atypical somatoform disorders". The revised third edition (DSM-III-R) mentions ORS in the text, stating that "convictions that the person emits a foul odor are one of the most common types of delusion disorder, somatic type." The fourth edition (DSM-IV), does not use the term ORS but again mentions such a condition under "delusional disorder, somatic type", stating "somatic delusions can occur in several forms. Most common are the persons conviction that he or she emits a foul odor from the skin, mouth, rectum or vagina." In the fifth edition (DSM-5), ORS again does not appear as a distinct diagnosis, but it is mentioned in relation to taijin kyōfushō (対人恐怖症, "disorder of fear of personal interaction").