Olfactory Reference Syndrome: Problematic Preoccupation with Perceived Body Odor

by Katharine Phillips, MD

This article was initially published in the Winter 2018 edition of the OCD Newsletter

Kyle is a 37-year-old single white male who believes that he has severe halitosis (bad breath) and flatulence, which makes him “stinky and smelly.” He states, “I know it’s true, because I can smell it, and why would people touch their face, sniff, and move away from me?” To minimize the awful odor that he is certain he emits, Kyle brushes his teeth for about an hour a day, which has damaged his gums and tooth enamel. He gargles with prescription-strength mouthwash about 20 times a day, wears lots of cologne, changes his underwear many times a day, and washes his clothes twice a day. Because he is embarrassed by the “horrible” odor he believes he emits, Kyle avoids most social situations. He does not date and has dropped out of college. Unable to work, he spends most of his time alone in his apartment. He states, “I have to stay alone, because I stink so much, and if I go out people will make fun of me.”

Kyle is experiencing olfactory reference syndrome (ORS), an underrecognized disorder characterized by preoccupation with the false belief that one emits a foul, unpleasant, or offensive body odor. This preoccupation causes significant distress or impairment in functioning (for example, avoidance of social situations). Although people with ORS believe that they really do smell bad, other people cannot detect the odor. ORS usually triggers excessive, repetitive behaviors such as repeatedly checking oneself for body odor, or excessive clothes laundering. As a result of these concerns, social anxiety and social avoidance are usually prominent, and the odor concerns are so distressing and impairing that suicidal thinking and suicide attempts are common (1-6).

ORS has many similarities to body dysmorphic disorder (BDD), which is characterized by distressing or impairing preoccupation with slight or nonexistent flaws in physical appearance, and obsessive-compulsive disorder (OCD) (2,3,6). Our understanding of ORS and its relationship to other disorders is limited by a lack of research studies. However, ORS is not a new phenomenon; it has been consistently described around the world since the 1800s as a distressing and often severely impairing disorder (2,3,7,8). The largest studies come from Japan, Canada, Nigeria, Saudi Arabia, Brazil, and the United States (1,6,9-13).


A Google search of ORS yields approximately 590,000 results, reflecting the public’s interest in this condition. Efforts were made to add ORS to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) (14), but research evidence was considered too limited to include ORS as its own disorder with full diagnostic criteria. Instead, DSM-5 lists ORS as an example of an “Other Specified Obsessive-Compulsive and Related Disorder” (14). DSM-5 provides a very brief description of ORS’s key clinical features, but does not include full diagnostic criteria or discussion of ORS in the text (14). However, the recently published International Classification of Diseases, 11th Edition (ICD-11), did add ORS as a new, separate disorder in the chapter of Obsessive-Compulsive or Related Disorders, alongside BDD and OCD (see Box) (15). It is hoped that inclusion of ORS in ICD-11 will foster much-needed research studies and enhance understanding and recognition of this often severe and underrecognized condition.


Preoccupation with Perceived Body Odor

Individuals with ORS are excessively preoccupied with the belief that they emit an unpleasant or foul body odor, most commonly bad breath or sweat (see Table 1). They believe that the foul odor emanates from body areas that correspond to the type of odor — for example, bad breath from the mouth or sweat from the armpits or skin. Occasionally, the perceived odor may smell like non-bodily odors, such as ammonia, detergent, or rotten onions. Most — but not all — people with ORS report actually smelling the odor.

Insight and Referential Thinking

Most people with ORS are completely convinced that they actually smell terrible, despite the fact that other people cannot detect an odor; very few recognize that their belief about the body odor is inaccurate (6). The likely explanation for this mistaken perception is that most people with ORS report that they actually smell the odor themselves (see Table 1) (6).

Alternatively, those who do not smell the odor base their belief on a misinterpretation of other people’s comments, gestures, or behaviors. For example, if someone opens a window, touches their nose, moves away, or says “It’s stuffy in here,” people with ORS typically — and mistakenly — believe that their unpleasant body odor is the reason for such behavior (see Table 1). This inaccurate belief that other people are taking special notice of them in a negative way because they smell bad is known as referential thinking (or as ideas or delusions of reference).

Excessive Repetitive Behaviors

People with ORS experience their preoccupation with body odor as highly distressing, and it triggers upsetting feelings such as depressed mood, anxiety, and self-consciousness. For this reason, nearly everyone with ORS feels compelled to perform repetitive behaviors intended to mitigate, check, mask, or reassure themselves about their perceived odor. The most common behaviors are smelling oneself, excessive showering, and frequent clothes changing (see Table 1).

Camouflaging the Perceived Odor 

People with ORS attempt to mask the perceived body odor, most often with excessive perfume or powder, chewing gum, excessive or strong deodorant, or mints (see Table 1). This behavior can occur repeatedly throughout the day.

Functional Impairment

ORS typically impairs functioning, which can range from mild to extreme; on average, impairment is severe in clinical samples of individuals with ORS (6). Nearly three-quarters of people with ORS report periods during which they avoided most social interactions because of their ORS symptoms, and about 50% report periods during which they avoided most of their important occupational, academic, or life activities because of ORS symptoms (6) (see Table 1). Some people are completely housebound because they feel too distressed, self-conscious, and embarrassed about the perceived odor to be around other people, or because they fear offending others with their smell.

High rates of psychiatric hospitalization, suicidal thoughts, suicide attempts, and completed suicide have been reported, which many individuals attribute primarily to their ORS symptoms (see Table 1) (1,6).


Commonly co-occurring disorders are a major depressive disorder, social anxiety disorder, drug or alcohol use disorders, obsessive-compulsive disorder, and body dysmorphic disorder (6).


In one study, 60% of individuals with ORS were female, and most were single (6). The prevalence of ORS is not known, but it is certainly more common than generally recognized (2,3,16).


The cause of ORS has not been studied and thus is not known. Like other psychiatric disorders, its cause likely has many genetic and environmental determinants. ORS has similarities to BDD, OCD, and social anxiety disorder, and thus it may share some etiologic and pathophysiologic characteristics with these disorders. For example, ORS may involve abnormalities in the brain’s olfactory system that cause olfactory hallucinations or extreme sensitivity to odors. However, this theory has not been studied, and it likely is not relevant to the minority of those with ORS who do not actually smell the odor.



No prospective medication studies have been done (either controlled or open-label studies). Case reports and small case series describe improvement with serotonin reuptake inhibitor (SRI) monotherapy, neuroleptic (antipsychotic) monotherapy, non-SRI antidepressants (such as tricyclic antidepressants), or a combination of a neuroleptic and antidepressant medication (2-4). In the author’s clinical experience, SRIs at high doses often effectively treat ORS.


Reports on psychotherapy are similarly limited to single case reports and small case series, which report improvement with behavioral therapy, cognitive behavioral therapy, and paradoxical intention (2-4). In the author’s experience, cognitive behavioral therapy – consisting of cognitive restructuring and advanced cognitive strategies for core beliefs, including self-esteem work and self-compassion; ritual prevention; and exposure-based exercises along with behavioral experiments that are tailored to ORS symptoms – can be effective. ORS’s clinical features appear most similar to those of BDD, and an evidence-based CBT treatment manual for BDD can be easily adapted to treat ORS symptoms (17).

 Non-Mental Health Medical Treatment

Nearly half of people with ORS seek non-mental health medical treatment for their perceived body odor (6), many before seeking mental health care (18); in one study, one third of people actually received such treatment (6). Patients may consult dentists, surgeons, and ear, nose, and throat specialists for supposed halitosis; proctologists, surgeons, and gastroenterologists for supposed anal odors; and other physicians such as dermatologists and gynecologists. Treatments such as a tonsillectomy for perceived bad breath or electrolysis of sweat glands for a perceived sweaty smell may be received. Such treatment does not appear to be effective for ORS symptoms and often leaves patients dissatisfied (6).

A neurologic workup, which may include an EEG, may sometimes be warranted to rule out a neurologic explanation (such as temporal lobe epilepsy or migraine aura) for perception of an odor that others cannot detect. This kind of evaluation is more relevant when concerns focus on nonbodily odors and occur only intermittently.


Current understanding of ORS is substantially limited by the very small number of published research studies on this condition. Nonetheless, it is important for clinicians and the public to be aware of ORS. Table 2 provides some clinical recommendations, based on current research-based knowledge about ORS and the author’s clinical experience. More research studies on all aspects of ORS are greatly needed to advance the understanding and treatment of this condition.

Katharine A. Phillips, MD is Professor of Psychiatry at Weill Cornell Medical College, Cornell University; an Attending Psychiatrist at New York-Presbyterian Hospital; and an Adjunct Professor of Psychiatry and Human Behavior at the Alpert Medical School of Brown University. Dr. Phillips is also a member of the IOCDF Scientific and Clinical Advisory Board, a contributing member to the IOCDF www.HelpforBDD.org website, and a regular presenter at the Annual OCD Conference. Please address correspondence to: Katharine Phillips, MD, Weill Cornell Psychiatry Specialty Center, 315 East 62nd Street, New York, NY 10065; Telephone: 646-962-2820; Fax: 646-962-0175; email: kap9161@med.cornell.edu


  1. Pryse-Phillips W. (1971). An olfactory reference syndrome. Acta Psychiatr Scand, 47:484–509.
  2. Phillips KA, Gunderson C, Gruber U, Castle DJ. (2006). Delusions of body malodor: the olfactory reference syndrome. In: Brewer W, Castle D, Pantelis C, editors. Olfaction and the Brain. Cambridge: Cambridge University Press; pp. 334–353.
  3. Feusner JD, Phillips KA, Stein DJ. (2010). Olfactory reference syndrome: issues for DSM-V. Depress Anxiety, 27:592–599.
  4. Phillips KA, Castle DJ. (2007). How to help patients with olfactory reference syndrome. Curr Psychiatr, 6:49–65.
  5. Begum M, McKenna PJ. (2010). Olfactory reference syndrome: a systematic review of the world literature. Psychol Med, 1–9.
  6. Phillips KA, Menard W. (2011). Olfactory reference syndrome: demographic and clinical features of imagined body odor. Gen Hosp Psychiatry, 33:398-406.
  1. Potts CS. (1891). Two cases of hallucination of smell. U Penn Med Mag, 226.
  2. Tilley H. (1895). Three cases of parosmia: causes and treatment. Lancet, 907–908.
  3. Yamada M, Shigemoto T, Kashiwamura KI, Nakamura Y, Ota T. (1977). Fear of emitting bad odors. Bull Yam Med School, 24:141–161.
  4. Prazeres AM, Fontenelle LF, Mendlowicz MV, de Mathis MA, Ferrão YA, de Brito NF, et al. (2010). Olfactory reference syndrome as a subtype of body dysmorphic disorder. J Clin Psychiatry, 71:87–89.
  5. Iwu CO, Akpata O. (1990). Delusional halitosis. Review of the literature and analysis of 32 cases. Br Dent J, 168:294–296.
  6. Osman AA. (1991). Monosymptomatic hypochondriacal psychosis in developing countries. Br J Psychiatry, 159:428–431
  7. Greenberg J, Shaw AM, Reuman L, Schwartz R, Wilhelm S. (2016). Clinical features of olfactory reference syndrome: an internet-based study. J Psychosom Res, 80:11-6.
  8. Diagnostic and Statistical Manual for Mental Disorders, 5th Edition. (2013). Arlington, VA; American Psychiatric Association.
  1. https://icd.who.int/browse11/l-m/en#/http://id.who.int/icd/entity/1119008568

16.       Zhou X, Schneider SC, Cepeda SL, Storch EA. (2018). Olfactory reference syndrome symptoms in Chinese university students: Phenomenology, associated impairment, and clinical correlates. Compr Psychiatry, 86:91-95.

17.       Wilhelm S, Phillips KA, Steketee G. (2013). Cognitive-Behavioral Therapy for Body Dysmorphic Disorder: A Treatment Manual. New York, NY: Guilford Press.

  1. Greenberg JL, Berman NC, Braddick V, Schwartz R, Mothi SS, Wilhelm S. (2018). Treatment utilization and barriers to treatment among individuals with olfactory reference syndrome (ORS). J Psychosom Res, 105:31-36.
  2. Eisen JL, Phillips KA, Baer L, Beer DA, Atala KD, Rasmussen SA. (1998). The Brown Assessment of Beliefs Scale: reliability and validity. Am J Psychiatry, 155:102-108.
  3. Phillips KA, Hart A, Menard W, Eisen JL. (2013). Psychometric evaluation of the Brown Assessment of Beliefs Scale in body dysmorphic disorder. J Nerv Ment Dis, 201:640-643.