- •
Medically unexplained symptoms (MUS) are a significant cause of morbidity for patients and of resource use for the health care system.
- •
Multiple diagnostic categories exist for patients with MUS.
- •
Risk factors for MUS include female gender, low socioeconomic status, and a history of trauma (specifically childhood sexual abuse).
- •
A careful history and physical examination is required for all patients with MUS, with additional diagnostic testing dictated by the patient’s symptom severity and chronicity.
Medically Unexplained Symptoms
Section snippets
Key points
Case 1: Ms D
Ms D is a 71-year-old woman with a history of peptic ulcer disease, metabolic syndrome, major depressive disorder, and osteoarthritis who presents for clinical follow-up with pain all over her body. She states that she cannot remember a time when her entire body did not hurt. She is also concerned about chronic abdominal pain.
On examination, her vital signs are within normal limits. She is tender to light palpation in every major muscle group. She is diffusely tender to light palpation on
Definitions
The terms MUS and somatization refer to symptoms that have minimal or no apparent basis in physical disease. These terms can also apply to patients with underlying disease explaining the presence of physical symptoms, but with a symptom burden out of proportion to what is expected. Some investigators criticize the use of the term MUS because of the ambiguity inherent in declaring a symptom to be unexplained, or unexplainable, and the importance of including diseases that may have psychological
Pathophysiology
The pathophysiology of MUS is poorly understood. Controversy exists as to whether the syndrome is predominantly physical or psychiatric, or a combination of the two, and whether the various named syndromes within the broader category of MUS or functional somatic syndromes are physiologically distinct, valid, and meaningful.12, 13 In one small study, 1 in 3 physicians thought that the cause of MUS was likely spiritual.14 Some evidence suggests a familial risk for somatization, although it
Symptoms
The most common symptom attributed to MUS is pain,1 including diffuse myalgias, arthralgias, low back pain, headache, and dysuria. Other possible symptoms include:
- •
Systemic symptoms: fatigue and insomnia
- •
Head and neck symptoms: tinnitus, pseudo–eustachian tube dysfunction, atypical facial pain, globus sensation27
- •
Cardiac symptoms: chest pain, palpitations, and dyspnea
- •
Gastrointestinal symptoms: bloating, nausea, abdominal discomfort, constipation, and diarrhea
- •
Genitourinary symptoms: chronic pelvic
Case 2: Ms L
Ms L is a 47-year-old woman with a history of hepatitis C and generalized anxiety disorder who presents with hemifacial pain and seizures. She states that she experiences episodes of throbbing pain that are migratory, occurring all over her scalp, lasting hours to days. It seems to occur more frequently when she has to leave the house to take her children to school or to come to medical appointments. No photophobia or phonophobia. No fevers, chills, or night sweats. No weight loss or nausea.
Diagnostic testing/imaging studies
A diagnosis of MUS can be made only after organic disease has been ruled out. It is therefore critical for clinicians to take a careful history and perform a thorough physical examination before making a diagnosis of MUS. History taking should be broad and comprehensive, with a specific focus on other symptoms that may suggest organic disease, and on patient attribution (to what does the patient attribute the symptoms?). The social history can be particularly useful in this setting as well,
Differential diagnosis
Somatization and major depressive disorder commonly coexist: 50% of patients with major depression present with MUS and between 45% and 95% of patients with major depression present with only somatic symptoms at the time of diagnosis.32 Depressed patients who lack a consistent primary care relationship are more likely to present with exclusively somatic symptoms.32 In addition, the severity of depression symptoms and decreased quality of life ratings are correlated with the presence of painful
Case 3: Mr C
Mr C is a 55-year-old man with a history of tobacco use, physical and sexual abuse in childhood, and Reinke edema. He presents to clinic for routine follow-up of postnasal drip, hoarseness, and a sensation that he needs to keep clearing his throat. He has had these symptoms for 2 years but only recently obtained health insurance, so presents to you for primary care follow-up. Five years before today’s visit, he underwent direct laryngoscopy, which showed polypoid degeneration of the true vocal
Management
Patients with MUS are highly variable with regard to their level of insight, focus of attention, and needs from medical providers35 and may provide cues to their providers regarding their need for emotional support or explanation for their symptoms.36 It can be particularly challenging for providers to discuss a diagnosis such as MUS, or one of its specific variants, with patients. The patient's experience is subjective, and the lack of objective evidence of organic disorder should not minimize
Future considerations/summary
In summary, caring for patients with MUS is challenging for health care providers. Even defining somatization syndromes is complex and controversial, reflecting the medical community’s limited understanding of the pathophysiology for this group of disorders. Although risk factors for MUS have been described and are well understood, little is known about how MUS can be prevented. Uncertainty in medicine, as in any human enterprise, is a given, but the difficulties in identification and treatment
References (55)
- et al.
The prevalence of somatization in primary care
Compr Psychiatry
(1984) - et al.
Common symptoms in ambulatory care: incidence, evaluation, therapy, and outcome
Am J Med
(1989) - et al.
The epidemiology of multiple somatic symptoms
J Psychosom Res
(2012) - et al.
Management of functional somatic syndromes
Lancet
(2007) - et al.
Functional somatic syndromes: one or many?
Lancet
(1999) - et al.
The cognitive behavioural model of medically unexplained symptoms: a theoretical and empirical review
Clin Psychol Rev
(2007) - et al.
Effects of childhood trauma on somatization in major depressive disorder: the role of alexithymia
J Affect Disord
(2013) - et al.
Trauma and medically unexplained symptoms towards an integration of cognitive and neuro-biological accounts
Clin Psychol Rev
(2007) What can we learn from a cross-national study of somatic distress?
J Psychosom Res
(2004)- et al.
Major depressive disorder in Latin America: the relationship between depression severity, painful somatic symptoms, and quality of life
J Affect Disord
(2005)
Pilgrimage of pain: the illness experiences of women with repetition strain injury and the search for credibility
Soc Sci Med
Personality and affect as determinants of medically unexplained symptoms in primary care; a follow-up study
J Psychosom Res
The comorbidity of DSM-III-R personality disorders in somatization disorder
Gen Hosp Psychiatry
The difficult doctor-patient relationship: somatization, personality and psychopathology
J Clin Epidemiol
Predictors of physician frustration in the care of patients with rheumatological complaints
Gen Hosp Psychiatry
Somatization increases medical utilization and costs independent of psychiatric and medical comorbidity
Arch Gen Psychiatry
Gender differences in the reporting of physical and somatoform symptoms
Psychosom Med
Somatization disorder in a family practice
J Fam Pract
Evidence for overlap between idiopathic environmental intolerance and somatoform disorders
Psychosom Med
Cognitive functioning in Gulf War illness
J Clin Exp Neuropsychol
Gulf war illness: symptomatology among veterans 10 years after deployment
J Occup Environ Med
Diagnostic and statistical manual of mental disorders
There is only one functional somatic syndrome
Br J Psychiatry
A spiritual problem? Primary care physicians' and psychiatrists' interpretations of medically unexplained symptoms
J Gen Intern Med
Alexithymia and somatization in general population
Psychosom Med
Medical and psychiatric symptoms in women with childhood sexual abuse
Psychosom Med
Sexual abuse and lifetime diagnosis of somatic disorders: a systematic review and meta-analysis
JAMA
Cited by (28)
The Filter Detection Task for measurement of breathing-related interoception and metacognition
2021, Biological PsychologyCitation Excerpt :However, inspiratory pressure also changes in physiological conditions, for example, simply as a result of increased inspiratory flow during activities such as exercise (Johnson, Weisman, Zeballos, & Beck, 1999) or hyperventilation induced by states of arousal (Gallego, Nsegbe, & Durand, 2001), but also as the result of reflex-mediated bronchoconstriction in response to cooling of the skin or upper airways (Koskela, 2007; Koskela & Tukiainen, 1995). Furthermore, it is now widely acknowledged that the perceptual system can be influenced by top-down factors such as attention, expectation and affect (Bogaerts et al., 2005, 2008; Van den Bergh, Witthöft, Petersen, & Brown, 2017; Janssens, Verleden, De Peuter, Van Diest, & Van den Bergh, 2009, 2011; Marlow, Faull, Finnegan, & Pattinson, 2019; De Peuter et al., 2004; De Peuter, Lemaigre, Van Diest, & Van den Bergh, 2008; Put et al., 2004; Stephan et al., 2016; Van den Bergh et al., 2004); a known issue in conditions where symptoms are discordant with objectively measured medical markers, such as in asthma (Boulay & Boulet, 2013; Janssens et al., 2009; Kendrick, Higgs, Whitfield, & Laszlo, 1993; Teeter & Bleecker, 1998) or those with medically unexplained symptoms (Isaac & Paauw, 2014; Nimnuan, Hotopf, & Wessely, 2001; Steinbrecher, Koerber, Frieser, & Hiller, 2011). Therefore, using a task that is able to dissociate measures such as perceptual sensitivity from decision bias and metacognition has great potential to fill an important unmet need in clinical practice.
Functional Respiratory Disorders in Children
2021, Pediatric Clinics of North AmericaCitation Excerpt :Functional respiratory disorders (FRDs) are those that are characterized by medically unexplained symptoms (MUSs).1
Satisfaction With Specific and Nonspecific Diagnoses
2019, Journal of Hand SurgeryBreathlessness and the body: Neuroimaging clues for the inferential leap
2017, CortexCitation Excerpt :Breathlessness is notorious as a symptom that is often out of proportion to objective markers of disease (Hayen, Herigstad, & Pattinson, 2013; Herigstad, Hayen, Wiech, & Pattinson, 2011; Jones, 2001; Lansing, Gracely, & Banzett, 2009; Mahler et al., 1996). While perceptual systems have traditionally been considered to encompass a stimulus followed by the brain's response, this relationship cannot explain the often-observed dissociation between perception and symptom extent, with extreme cases manifesting as medically unexplained symptoms (Isaac & Paauw, 2014; Nimnuan, Hotopf, & Wessely, 2001). As it is the perception of symptoms that leads to their debilitating consequences, an overhaul is required in the way we consider the brain's interaction with incoming sensory information.
What's ‘difficult’? A multi-stage qualitative analysis of secondary care specialists' experiences with medically unexplained symptoms
2016, Journal of Psychosomatic ResearchCitation Excerpt :It is common in medical practice that people consult for symptoms that elude medical explanation. In the U.K., this phenomenon is currently referred to as ‘medically unexplained (physical) symptoms’ (MUS) [1], yet the term is contested and a plethora of competing terms exist, e.g. somatisation disorder, somatoform disorder, abnormal illness behaviour or functional symptoms [2–7]. The terminological heterogeneity not only mirrors the fact that such conditions often fall between specialities [8], but also reflects the lack of agreement about the conceptual basis of this phenomenon [9–11].
The authors have no financial disclosures.