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.

TABLE 1: Key Clinical Features of Olfactory Reference Syndrome

Clinical Feature% of Patients, or Mean ± Standard Deviation
Source of Odor2
Under Breasts5.00%
Total different # of sources2.9 ± 1.4
Description of Odor2
Bad breath75.00%
Other smell365.00%
Other Characteristics of Odor
Olfactory hallucinations85.00%
Level of insight (Brown Assessment of Beliefs Scale [BABS])420.6 ± 3.7 (delusional/absent insight range)
Insight (% with delusional/absent insight on BABS)484.60%
Referential thinking (ideas or delusions of reference; lifetime)88.30%
Excessive Compulsive Behaviors2
Smelling self80.00%
Changing clothes50.00%
Seeking reassurance45.00%
Dieting/unusual food intake45.00%
Brushing teeth40.00%
Laundering clothes30.00%
Comparing to other people30.00%
Other behavior530.00%
At least one compulsive behavior95.00%
Total # of compulsive behaviors4.2 ± 2.0
Items Used to Mask Odor2
At least one item used to mask odor100.00%
Total # of items used to mask odor4.0 ± 2.2
Course of Illness 
Age of ORS onset15.6 ± 5.7
ORS onset < 18 years old65.00%
Course of odor concerns over time
One set of odor(s) that started at same time and did not change38.90%
New odors added to ongoing previous odors44.40%
Complex additions and remissions of odors16.70%
Functional Impairment Attributed to ORS (lifetime)
Avoidance of social interactions73.70%
Avoidance of occupational/academic/role activities47.40%
Housebound for at least 1 week40.00%
GAF (Global Assessment of Functioning) (current)747.5 ± 13.2
History of suicidal ideation68.40%
History of suicidal ideation attributed primarily to ORS47.40%
Attempted suicide31.60%
Attempted suicide primarily due to ORS15.80%
History of physical violence50.00%
History of physical violence attributed primarily to ORS21.40%
Treatment (lifetime)
Psychiatric hospitalization52.60%
Psychiatric hospitalization attributed primarily to ORS31.60%

Table Notes

  • Table is adapted from Phillips KA, Menard W. Olfactory reference syndrome: demographic and clinical features of imagined body odor. General Hospital Psychiatry 2011;33:398-406
  • Total is greater than 100% because some patients reported multiple odors, odors that emanated from multiple body areas, multiple repetitive behaviors, or multiple masking strategies.
  • Other smells were (n=1 for each): “like wearing sanitary napkins too long,” “unpleasant vaginal odor,” ammonia, “bad,” “body odor/mucus/post nasal drip,” “body odor/rotten odor/morning breath,” “hard/unpleasant smell,” “like 5 day-old food and cigarette smoke,” oily-fishy smell,” and “vegetable soup/putrid body (odor).”
  • The Brown Assessment of Beliefs Scale (BABS) classifies false beliefs as characterized by excellent, good, fair, poor, or absent insight/delusional belief (19,20). On the BABS, mean scores for ORS are in the absent insight/delusional range, for BDD are in the poor insight range, and for OCD are in the good insight range.
  • Other excessive behaviors were as follows; scrapes tongue/coughs to remove bacteria on tonsils/talks softly/uses feminine wash, scrapes back of tongue/checks tonsils to pull mucous off them, uses spoon to scrape skin on tongue and inside of mouth, checks breath by blowing into nose/drinking water, frequent haircuts/avoids hats, drinks lots of fluids.
  • Other items/behaviors used to mask the odor were as follows (n=1 for each); spraying alcohol on self and furniture/wearing heavy underwear, putting cornstarch under feet, putting toilet paper in underwear, crossing legs/putting toilet paper in underwear, using air fresheners.
  • The mean GAF score reflects serious symptoms or serious functional impairment.
  • Physical violence was defined as motor behavior that physically injured another person or caused significant property damage.

TABLE 2: Key Recommendations for Clinical Practice1

Be familiar with ORS and its clinical features; it is more common than generally recognized.
Do not assume that ORS is simply a symptom of another psychiatric condition, such as depression, a psychotic disorder, BDD, or OCD; focus specifically on ORS when providing treatment.
Screen patients for ORS, especially those with high levels of social anxiety or social avoidance, referential thinking, or performance of the repetitive or camouflaging behaviors in Table 1.
For selected patients, consider a neurologic workup to rule out a neurologic explanation for olfactory hallucinations, such as temporal lobe epilepsy. 
Medication is strongly recommended for patients with more severe ORS symptoms, especially those who are very impaired in terms of functioning, are severely depressed, or are more highly suicidal. Medication is also a good option when symptoms are mild or moderate in severity, especially if co-occurring disorders are present that may respond to similar medication (such as BDD, OCD, social anxiety disorder, or depression).
Serotonin-reuptake inhibitors — at high doses if lower doses are not effective — are recommended as the first-line medication for ORS (similar to BDD and OCD).
Atypical neuroleptics (such as aripiprazole or risperidone) may potentially be helpful in combination with an SRI (similar to BDD and OCD). These medications should especially be considered if an adequate trial with an SRI is not sufficiently helpful or if problematic agitation, very severe depression, marked impairment in functioning, worrisome suicidal thinking, or suicidal behavior are present.
Cognitive-behavioral therapy that is tailored to ORS is also recommended, especially for more severe ORS symptoms. It is also a good option when symptoms are mild or moderate in severity. Core components of CBT appear to consist of cognitive therapy, exposure with behavioral experiments, and ritual prevention. 
Given the presence of obsessions, repetitive behaviors (rituals), poor or absent ORS-related insight, depressive symptoms (usually present), and often-prominent social anxiety and avoidance, CBT for ORS appears most similar to that for BDD. In the author’s experience, an evidence-based treatment manual for BDD can easily be modified to effectively treat ORS17.
Many individuals with ORS desire non-mental health medical treatment for ORS concerns, such as removal of sweat glands or a tonsillectomy, which does not appear to be effective.
Because ORS-related insight is usually absent (i.e., ORS beliefs are usually delusional in nature), and because many individuals with ORS desire non-mental health medical treatment for ORS concerns, motivational interviewing is often needed to engage and retain patients in mental health treatment.

Table Notes

Because research evidence on ORS is very limited, these recommendations are also based on the author’s clinical experience with ORS and may change as research studies are done.

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


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