Medically unexplained physical symptoms

Medically unexplained physical symptoms (MUPS or MUS) or Persistent Physical Symptoms are symptoms for which the doctor is unable to find a cause, for example unexplained dizziness, pain without a known cause, or unexplained tiredness.

Medically unexplained symptoms may be mild, and can resolve within a few weeks without treatment, but some are more persistent. In practice, "medically unexplained" may be used to extremely broadly to describe either symptoms of a diagnosis not yet fully understood by medicine, especially ME/CFS, fibromyalgia or irritable bowel syndrome, or symptoms that are not known to be linked to a medical condition, or symptoms a medical professional judges to be out of proportion to the related physical cause or illness.

Classification and alternative names
Patients with MUS or MUPS are sometimes referred to as having Functional Somatic Symptoms (FSS) or diagnosed as Bodily Distress Syndrome (BDS) - both of which are mental illnesses - despite being classified as physical illnesses under the World Health Organization's current ICD-10 classification, and the latest ICD-11 classification. Somatoform disorders, Somatic symptom disorders, Conversion disorder, and Functional Neurological Disorder (FND) are also regarded as medically unexplained symptom and classified as purely psychological symptoms conditions only in the DSM psychiatric manual.

MUS review linked to PACE trial
In the UK there is currently a PROSPERO systematic review of medically unexplained symptoms and their treatments being undertaken by a number of authors including Peter White, first author of the controversial PACE trial for ME/CFS, into MUS.

Somatization and psychologization
A key assumption often made is that medically unexplained physical symptoms are symptoms which have no physical cause - rather than no known physical cause, and so are assumed be caused by somatization: the physical expression of emotional distress. Symptoms, or entire diagnosed illnesses such as ME/CFS or fibromyalgia, are assumed to have no underlying illness process but to have "psychosomatic" symptoms or "psychogenic illness".

The MUS approach has been used inappropriately to reclassify diagnosed physical illness, including ME/CFS, as a mental health, which can then result in inappropriate treatment,  for example medical neglect, and in some severely ill patients, forced psychiatric treatment and forced exercise therapy combined with medical neglect, factors which contributed to the death of Sophia Mirza from ME/CFS.

Absence of evidence of a physical cause
Medically unexplained symptoms are often referred to as lacking evidence of any organic pathology (physical cause) - but have been criticized as overly inclusive for including patients with symptoms judged to be out of proportion to the illness or injury; this is problematic because it relies not on medical or psychological tests for MUS but on a doctor's current knowledge of a diagnosed illness or injury, and on medical science's current expectation of particularly severe cases of the each diagnosis.

A patient with a serious medical illness can find themselves also diagnosed with a "medically unexplained physical symptoms" label such as Somatic symptom disorder because of their help-seeking behavior, worry over their health or reporting a disproportionate degree of symptoms. For example, a doctor or psychiatrist assessing a person with very severe ME may be unaware that paralysis, seizures and speech problems can occur, and the illness can, in some cases, kill, so this lack of knowledge may lead to an incorrect diagnosis of MUS, with cognitive or behavioral treatments that may cause significant harm, and a denial of specialist treatment. The classification as a mental illness allows for a patient to be forcibly treated if they are judged to be lacking mental capacity, something which can occur in severe ME due to be severe cognitive and concentration problems, or episodes or speech loss and paralysis that prevent communication.

Historically, illnesses that were previously misunderstood or not yet identified were blamed on patients' personality, for example William Henry Day's concept of the "migraine personality" in 1878, Diamond and Dalessio (1973) claims that "up to 90% [of those with migraines] have a psychogenic basis for their complaint", patients were labeled as "untrustworthy", "drug-seeking", or as potential malingerers. Lupus, multiple sclerosis, and Lyme disease are all examples of illnesses that were previously assumed to have a psychological origin simply because of the "absence of evidence" of a physical cause.

English (2000) states that "Absence of evidence may reflect insufficient research, inadequate technology, poor methods, flawed paradigms, closed minds, or lack of clinical experience; for example, in 1980, there was no clear evidence that AIDS was viral—blood products were considered “safe.”"

Criticism and controversy
The whole MUS concept of lumping different syndromes or groups of symptoms further - all of which are then regarded as "non-diseases" - has been criticized as unscientific and lacking evidence - especially with wrongly including ME, which is a recognized neurological disease. In the UK, the effect of this is that patients regarded as having MUS conditions or symptoms are treated under the Improving Access to Psychological Therapies (IAPT) programme, a mental health-only approach which does not have the facilities or skills to treat complex and severe physical health problems.

The inclusion of ME/CFS under MUS has been heavily criticized by advocates and patients with ME, especially in the UK which is obliged to follow the World Health Organization's classification system - which recognizes ME / CFS / Post-viral syndrome under neurological diseases, and excludes then from other categories.

An article in Positive Health stated that MUS will divert funding from the UK's mental health system by wrongly including ME/CFS.

The Countess of Mar has asked questions about the problems of MUS and ME/CFS in the UK's House of Lords.

Dr James Coyne has found that Peter White, lead author of the highly controversial PACE trial and advisor to the UK Department for Work and Pensions, did not disclose his financial interests with health insurers for the PROSPERO review.

Patient advocates have critiqued the basis and motive of the rollout of MUS in the UK.

Costs of medically unexplained symptoms
A highly influential study by Bermingham et al attempted to calculate the health care costs of patients with MUS, but incorrectly included costs of treating diseases that are not classified as MUS, including ME/CFS.

Further controversy has erupted with the repeated incorrect references to Bermingham et al. which have been published in further reviews and articles by influential journals. Dr David Tuller, a public health professional at Berkeley has repeatedly highlighted this, contacting Carolyn Chew-Graham and others who incorrectly cited the paper and the journals that published it to request corrections.

Medical neglect
Medically unexplained symptoms guidance recommendations includes avoiding doing "unnecessary" diagnostic tests due to the believe in the risk of "iatrogenic harm" and patients may be taught to avoid "symptom focusing", leaving people with a physical illness at risk of medical neglect due to the lack of investigation of comorbidities, or failure to correctly diagnose other causes for symptoms or other illnesses, and lack of biomedical treatment.

Biopsychosocial model
The biopsychosocial model (BPS) is frequently used to provide treatment for medically unexplained physical symptoms. A key part of this model is the use of psychological approaches, often including a form of psychotherapy called cognitive behavioral therapy. In patients with ME/CFS, patient groups and a number of different authors, have reported that the biopsychosocial approach has led to substantial rates of harm and multiple types of harm have been identified in this patient group. A survey of over 2,000 British patients with ME/CFS was conducted in 2019 to help inform the revision of the NHS treatment guidelines, and found that the treatment was more harmful then helpful. The survey reported that more than 1 in 5 patients developed new symptoms while undergoing cognitive behavioral therapy for ME/CFS, 26% said their physical health had deteriorated as a result, with only 16% reporting improved physical health. Alarmingly, 26% found their mental health deteriorated with this psychological approach.

The psychologization of patients' illness in the absence of psychological symptoms assumes that psychological help must be needed or beneficial in patients with medically unexplained symptoms, despite the fact that an unknown number of patients may have symptoms caused by an undiagnosed medical condition, a medical condition not yet recognized by modern science, or a recognized medical condition like ME/CFS that is not fully understood yet.

Patient experiences
Patients with medically unexplained physical symptoms have described many types of negative medical encounters, including:
 * harmful medical advice or treatment
 * inappropriate psychological explanations) (the psychologization of symptoms)
 * disbelief and disrespectful treatment from doctors and health care professionals
 * marginalization of patients' experiences
 * lack of physical examination and denial of tests or access to specialists that other patients receive
 * failure to investigate new or worsening symptoms
 * increased risk of psychiatric medications bring inappropriately prescribed
 * disregarding patients' knowledge and autonomy
 * the use of the MUS label to challenge the validity of patients' existing diagnosis of ME/CFS
 * gender bias: female patients are more likely to be diagnosed with medically unexplained physical symptoms

Improving Access to Psychological Therapies
Improving Access to Psychological Therapies (IAPT) is the treatment arm of the MUS rollout in the UK. It has been accused of diverting millions in mental health care funding to patients without mental illness, and for its lack of effectiveness in patients with MUS.

The Journal of Health Psychology published Michael Scott's Improving Access to Psychological Therapies (IAPT) - The Need for Radical Reform, which used the PACE trial as an example of inflating rates of recovery from psychological treatments, and concluded that the IAPT similarly had little evidence to justify the treatments even for psychological conditions.

The editor of the Journal of Health Psychology, Dr David Marks, published the editorial IAPT under the microscope in July 2018, which concluded "A service based on the promise of savings by taking people off benefits is a political hot potato. There is an urgent need for an independent review of IAPT by impartial experts."

Articles and research critical of lumping ME/CFS into MUS

 * 2013, The Somatic Symptom Disorder in DSM 5 risks mislabelling people with major medical diseases as mentally ill - (Full text)
 * 2017, Contesting the psychiatric framing of ME/CFS (Full text)
 * 2017, Absence of evidence - focusing on ME/CFS (Full text)- Margaret Williams
 * 2017, Medically Unexplained Symptoms (MUS): Faults and Implications (Full text)
 * 2019, Bodily Distress Syndrome: Concerns About Scientific Credibility in Research and Implementation (Full text)

Notable studies and articles

 * 2010, The cost of somatisation among the working‐age population in England for the year 2008–2009 (Full text)
 * 2015, Managing medically unexplained illness in general practice (Full text)
 * 2017, “It´s incredible how much I´ve had to fight.” Negotiating medical uncertainty in clinical encounters (Full text)
 * 2018, Nosological journey of somatoform disorders: From briquet's syndrome to bodily distress disorder (Full text)
 * 2018, Why Bioethics Should Be Concerned With Medically Unexplained Symptoms (Full text)

Letters, talks and blogs

 * M.E. must continue to be classified as neurological - Action for ME
 * 2019, It's time to pay attention to Chronic Fatigue Syndrome
 * 2015, Dr Jim Bolton presents Medically Unexplained Symptoms

Learn more

 * Absence of Evidence - Margaret Williams
 * Medically unexplained symptoms - Royal College of Psychiatrists
 * Trial by Error: Some thoughts on MUS and Bermingham: My letter to Professor Payne - David Tuller
 * Medically unexplained symptoms - NHS
 * Wikipedia - Medically unexplained physical symptoms