Unexplained and exaggerated symptoms

Author: Dr Tony Williams FFOM, Consultant Occupational Physician, Working Fit Ltd

Date: 24th October 2015

Medically unexplained symptoms

Patients often seek medical care with symptoms that cannot be readily explained by obvious pathology. 

A study in Germany found two thirds of reported symptoms in primary care were unexplained(Steinbrecher et al., 2011).  The twelve month prevalence of somatoform disorders was 22.9%, mental health disorders had a prevalence of 37.1% while for affective disorders it was 12.4% and 11.4% for anxiety disorders.  Somatoform disorder was comorbid with at least one other mental disorder in 43.2% of cases, most frequently anxiety or depression.

A study in UK found 18% of consecutive attenders had medically unexplained symptoms (Taylor et al., 2012) with insecure emotional attachment noted in 28%.  A high mean annual consultation frequency was noted at 5.24 [95% CI 4.79-5.69].  The association between presenting with MUS and insecure emotional attachment was particularly strong in those who believed there was a physical cause for their symptoms [OR 9.52, 95% CI 2.67-33.93]. 

A biological cause was only found in 26% of the ten most common presenting symptoms in primary care (Kroenke and Mangelsdorff, 1989).

Worldwide studies suggest 25-50% of primary care patients present with medically unexplained symptoms (Edwards et al., 2010).

A meta-analysis showed a small to moderate relationship between alexithymia and somatization, with difficulty in identifying feelings showing the strongest association with somatic symptom reports (De Gucht and Heiser, 2003).

A study estimated the total aggregate cost of somatization among working adults in England was £18 billion per year in 2008-9 (Bermingham et al., 2010).


There has been much debate about how best to describe unexplained or exaggerated symptoms, and how to relate this to diagnosis and treatment.  Medicine has always classified disease and disorder in a methodological and hierarchical way in order to help doctors understand the underlying problems and to assist in diagnosis and treatment.  These classifications are necessarily artificial constructs, particularly in psychological and psychiatric classifications where disorders are not diagnosed by objective standardized laboratory tests but by answers to questions and observed behavior. 

The classification used worldwide is the World Health Organisation’s International Classification of Diseases, currently in its tenth version (ICD 10).  The use of any classification in modern medicine involves integration into very complex IT systems particularly for reimbursement and resource allocation in health systems and this takes time.  ICD codes also have different optional subgroupings at National levels.  The result can be very complex.  The ICD10 system development started in 1983 and was completed in 1992 but has yet to be fully adopted by the US healthcare system who still use ICD9 for administrative purposes and plan to implement ICD10-CM and ICD10-PCS by October 2015.  The NHS uses a different coding system ‘OPCS’ for clinical coding of hospital procedures. 

As medicine develops and advances, classifications are regularly reviewed and adjusted to reflect current knowledge and understanding.  This leads to changes in terms, and the position of these terms within the hierarchy.  Patients may well find this particularly difficult, where they have accepted a particular term such as ‘myalgic encephalitis’ (ME) with an assumption that there is some underlying inflammatory process involving muscles and brain, only to have this term superseded by ‘chronic fatigue syndrome’ (CFS) where the words have a very different meaning but the underlying condition is the same.

ICD10 uses an alphanumeric code reflecting the hierarchical structure.  In ICD 10 mental and behavioural disorders are grouped under ‘F’, so for example Somatoform Disorders are F45, Somatization Disorder is F45.0, Undifferentiated Somatoform Disorder is F45.1, Hypochondriasis is F45.21 and Pain Disorder Exclusively Related to Psychological Factors is F45.41.  The classification of these conditions is further confused by their presentation as physical problems.  ICD 10 also includes the disorder Fibromyalgia M79.7 under ‘soft tissue disorders’ although there is no evidence for any soft tissue disorder in the condition.  The disorder Postviral Fatigue Syndrome G93.3 is included under ‘other disorders of the brain’ although there is no evidence for any physical ‘brain disorder’, and this code includes chronic fatigue.  This potential ‘dual coding’ is unhelpful to patients and clinicians and reinforces the view that this is a physical organic pathological condition even though there is no evidence that this is the case.

Practice often differs from policy and procedures, and the American Psychiatric Association has historically always produced its own system of classification for mental health disorders, Diagnostic and Statistical Manual of Mental Health Disorders currently in its fifth edition (DSM 5).  This, too has worldwide recognition.  There is no alphanumeric coding, just a labeling system in a hierarchical structure.  Many of the terms used are the same as ICD10 but some are different, and the hierarchical organization differs.  While it would seem best to stick with the worldwide ICD system, we have to recognize that ICD10 reflects the practice of medicine some 25-30 years ago while DSM 5 reflects current practice.  The differences in understanding and practice are perhaps most striking when considering unexplained or exaggerated symptoms, so most practitioners will lean to DSM 5 rather than ICD10.

The practice of medicine has changed, with the concept of patient autonomy and doctor-patient partnerships.  The views of patients are given much more importance, and this has at times led to demands from patients and patient groups to avoid labels and terminology they do not like, and use labels and terminology they prefer.  We now have, in some areas of medicine, a significant conflict between patients who want labels and terminology that reflects their own beliefs as opposed to ones that reflect the objective realities identified in peer-reviewed research and clinical practice.  In some cases a compromise is reached with for example use of the combined term ‘CFS/ME’.

Terminology has to be used with care.  There is much confusion, misinformation, disinformation and inappropriate treatment that results from a lack of differentiation between descriptive terms and diagnoses.  Perhaps the most obvious is in the use of the term ‘depression’.  ‘Depression’ is both a symptom and a disorder.  The symptom of depression is almost universally experienced at times, but the clinical disorder in its severe form is much less common and potentially very disabling with a significant risk of suicide.  On the one hand, clinicians may incorrectly assume that a patient needs extensive treatment and will be at significant future risk because of use of the term ‘depression’.  On the other hand the general public who see many of their friends and relatives diagnosed inappropriately with ‘Depressive Disorder’ when they just have low mood may not take the diagnosis seriously.  Even experienced specialists often opt for the label ‘depression’ out of habit when ‘Adjustment Disorder’ is the correct term.

For clarification, throughout this text where a specific diagnostic label is used, it is placed in italics.

The term ‘Medically unexplained symptoms’

Doctors have generally grouped conditions such as chronic fatigue, chronic pain and irritable bowel into ‘medically unexplained symptoms’ to reflect the fact that patients present with often profound symptoms with no identifiable underlying pathological process.  Various labels have been applied in the past such as ‘Somatoform Disorder’, but the emphasis has always been on a lack of medical explanation for symptoms.

While this has been helpful for doctors, it has often been very unhelpful for patients.  While some patients have been reassured to know there is no significant medical cause, others have developed a strong belief that there must be a cause as the symptoms are so substantial, and have embarked on a journey to seek a medical explanation.  This journey may involve visits to numerous specialists, numerous often very expensive investigations and often visits to non-medical practitioners seeking alternative therapies, none of which are appropriate. 

Patients often group together for ‘support’, a process that can lead to reinforcement of inappropriate beliefs and a collegiate anger and frustration that can convert a journey of discovery in to something approaching expeditionary warfare.  Leading doctors have been subjected to death threats and campaigns of violence (Hawkes, 2011). 

Predisposing factors

A number of factors may lead to or contribute to development of somatic symptoms. 

Pain susceptibility varies and evidence shows some people have a clear genetic and biological vulnerability related to altered pain pathways and control mechanisms for pain.

People with early traumatic experiences including violence, abuse and deprivation are more likely to somatise.

People learn illness behavior through the reaction of others or the behavior or others.  Spouses learn from each other, children learn from adults and behavior trends can often be seen in families.  Learning is particularly influenced by illness attention, and lack of response to standard symptoms of distress.

There may be cultural or social factors.  Stigmatisation of psychological distress may lead to people adopting physical symptoms to gain support from family and friends or engage with medical care.  An employer may require a medical justification for a social requirement, forcing the medicalization of distress in order to achieve a required response.


The term ‘alexithymia’ refers to a poorly developed language of emotions.  Individuals have difficulty experiencing, expressing and describing emotion.  Some studies show a strong association between alexithymia and somatic symptoms but there is no clearly defined aetiological role.  It is, however, likely that some patients somatise because of an inability to express their distress as an emotion.

Co-existence with other disorders

There is considerable co-morbidity with other mental health disorders, and somatic symptoms may lead on to development of Major Depressive Disorder and Panic Disorder.  Co-morbidity can exacerbate symptom severity and functional impairment, and delay or prevent response to treatment.  It is therefore important to ensure a full psychiatric assessment prior to starting treatment, and in some cases to treat the co-morbid condition first before embarking on evidence-based treatments for the somatic symptoms.

Subgroups of patients and differing behaviours

A qualitative study into patients with somatic symptom disorder found three patterns of perceptions and behaviours, all with the common thread of current or past family dysfunction (Dwamena et al., 2009).

  • Coping high utilisers.  These achieve success in their lives and a have a degree of psychological insight. They neither focus on their symptoms nor display significant health anxiety. They want explanations for their symptoms.
  • Classic high utilisers.   These focus excessively on their vague symptoms, demonstrate little psychological insight and/or express strong entitlement that they should be excused from normal social obligations.
  • Worried high utilisers.  These demonstrate high health anxiety and become angry and complain about their health care when they perceive resistance to their expectations and demands.

BERMINGHAM, S. L., COHEN, A., HAGUE, J. & PARSONAGE, M. 2010. The cost of somatisation among the working-age population in England for the year 2008-2009. Ment Health Fam Med, 7, 71-84.

DE GUCHT, V. & HEISER, W. 2003. Alexithymia and somatisation: quantitative review of the literature. J Psychosom Res, 54, 425-34.

DWAMENA, F. C., LYLES, J. S., FRANKEL, R. M. & SMITH, R. C. 2009. In their own words: qualitative study of high-utilising primary care patients with medically unexplained symptoms. BMC Fam Pract, 10, 67.

EDWARDS, T. M., STERN, A., CLARKE, D. D., IVBIJARO, G. & KASNEY, L. M. 2010. The treatment of patients with medically unexplained symptoms in primary care: a review of the literature. Ment Health Fam Med, 7, 209-21.

HAWKES, N. 2011. Dangers of research into chronic fatigue syndrome. BMJ, 342, d3780.

KROENKE, K. & MANGELSDORFF, A. D. 1989. Common symptoms in ambulatory care: incidence, evaluation, therapy, and outcome. Am J Med, 86, 262-6.

STEINBRECHER, N., KOERBER, S., FRIESER, D. & HILLER, W. 2011. The prevalence of medically unexplained symptoms in primary care. Psychosomatics, 52, 263-71.

TAYLOR, R. E., MARSHALL, T., MANN, A. & GOLDBERG, D. P. 2012. Insecure attachment and frequent attendance in primary care: a longitudinal cohort study of medically unexplained symptom presentations in ten UK general practices. Psychol Med, 42, 855-64.