How do Doctors Diagnose Fibromyalgia?
By definition, fibromyalgia is a disorder of chronic, widespread pain and tenderness. Chronic indicates the pain and tenderness have been present continuously for at least 3 months. Widespread means the pain and tenderness are on both sides of the body, above and below the waist, including the axial spine (usually the paraspinal, scapular, and trapezius muscles). While identification of fibromyalgia patients by the original 1990 American College of Rheumatology (ACR) classification criteria required a specialized physical examination to quantify tender-point count that many providers have not been trained to perform,  the 2010 ACR diagnostic criteria allow for diagnosis by history without specialized training. 
In addition to chronic, widespread pain and tenderness, the 2010 diagnostic criteria require that fibromyalgia patients have significant symptoms of fatigue, unrefreshed sleep, and cognitive dysfunction (difficulties with thinking and remembering), along with numerous somatic symptoms. However, fibromyalgia is a diagnosis of exclusion and patients must be thoroughly evaluated for the presence of other disorders that could be the cause of symptoms before a diagnosis of fibromyalgia is made.
For this reason, all patients require a thorough history, physical examination, and laboratory evaluation before they are diagnosed with fibromyalgia. Approximately one third of patients identify a specific event (eg, illness, stress or injury) that precipitated the development of fibromyalgia. However, most patients spontaneously develop symptoms without an identifiable stressor. In addition, while some patients have a history of childhood trauma, the majority do not and it should not be assumed that all fibromyalgia patients have a history of abuse.
2010 ACR diagnostic criteria: Physician assessment
The 2010 ACR diagnostic criteria require physicians to evaluate patients by questioning to determine scores on a widespread pain index (WPI) and a symptom severity (SS) scale.
The WPI quantifies the extent of bodily pain on a 0-19 scale by asking patients if they have had pain or tenderness in 19 different body regions (shoulder girdle, hip, jaw, upper arm, upper leg, lower arm, and lower leg on each side of the body, as well as upper back, lower back, chest, neck, and abdomen) over the past week, with each painful or tender region scoring 1 point.
The SS scale quantifies symptom severity on a 0-12 scale by scoring problems with fatigue, cognitive dysfunction and unrefreshed sleep over the past week each on a scale from 0-3, as follows:
- 0 = No problem
- 1 = A slight or mild problem (generally mild or intermittent)
- 2 = A moderate or considerable problem (often present and/or at a moderate level)
- 3 = A severe, continuous, life-disturbing problem
These scores are summed for a measure of the physician’s impression of the number of somatic symptoms the patient has on a 0-3 scale, as follows:
- 0 = No symptoms
- 1 = A few symptoms
- 2 = A moderate number of symptoms
- 3 = A great deal of symptoms.
A patient is diagnosed with fibromyalgia if the following three conditions are met:
- The WPI score is 7 or higher and the SS scale score is 5 or higher or the WPI is 3-6 and the SS scale score is 9 or higher
- The symptoms have been present at a similar level for at least 3 months
- The patient does not have another disorder that would otherwise explain his or her pain
Modified 2010 ACR diagnostic criteria: Patient self-assessment questionnaire
In the 2010 ACR diagnostic criteria, symptom severity is determined by the physician. However, since fibromyalgia is a subjective disorder, patients are the ultimate source of information on the severity of their symptoms. Physicians tend to underestimate patient symptom severity,  and physician scoring of symptom severity can lead to underdiagnosis.
By their nature, the fibromyalgia diagnostic criteria are amenable to administration as a patient self-report questionnaire that can limit underdiagnosis and speed clinical evaluation since patients can complete the assessment prior to entering the examination room. Such a self-administered patient questionnaire based on the fibromyalgia diagnostic criteria has been shown to accurately identify fibromyalgia patients.  This questionnaire is divided into 3 sections.
The first section assesses the distribution of bodily pain using the same 19 body areas as in the WPI, with patients marking each area yes or no to indicate the presence of pain or tenderness in that area over the past week. Patients score 1 point for each painful or tender body area, yielding a self-report WPI score between 0 and 19, analogous to the WPI score in the physician-assessed diagnostic criteria.
The second section evaluates the severity of problems with daytime fatigue, nonrestorative sleep, and cognitive dysfunction (trouble thinking and remembering) using separate questions scored on 0-3 scales that range from 0 = no problem to 3 = a severe problem.
The third section asks patients whether they have experienced pain or cramps in the lower abdomen, depression, or headache during the past 6 months, with patients scoring 1 point for each positive symptom.
Scores from the second and third sections are summed to yield a 0-12 SS scale score analogous to the SS scale score in the physician-assessed diagnostic criteria. Scores from the WPI and SS scale sections are summed to yield a 0-31 index termed the polysymptomatic distress scale (PSD). Patients with a PSD scale score of 13 or more are diagnosed with fibromyalgia if the symptoms have been present at a similar level for at least 3 months and the patient does not have another disorder that would otherwise explain the symptoms.
The goal of the physical examination is to confirm the diagnosis, rule out concomitant systemic diseases, and recognize common coexisting conditions. Except for painful tender points and, perhaps, signs of deconditioning, physical examination findings are typically normal in fibromyalgia patients. The tender-point examination should be performed first during the physical examination, because other aspects of the examination may influence sensitivity of tender points.
Performance of the tender-point examination can be improved by using the manual tender-point survey (MTPS) method.  The MTPS has been shown to reduce variability in performance of the tender-point examination and identify fibromyalgia patients with high sensitivity and specificity.
The MTPS consists of standardized components including the following:
- Location of the tender-point sites
- Patient and examiner positioning
- Order of tender-point examination
- Pressure application technique
- Pain severity rating scores
Eighteen tender points are palpated at standard locations arranged symmetrically on the body, along with 3 control points. See the image below.
The thumb pad of the examiner’s dominant hand is used to apply pressure to each evaluation site one at a time during the tender-point examination. This allows the examiner to use important tactile cues and is as reliable as the use of a dolorimeter (see Pressure algometry, below).
The procedure is as follows: First, visually locate the evaluation site. Then, with the thumb pad, press perpendicularly into the evaluation site with gradually increased pressure for 4 seconds until a pressure of 4 kg is reached, roughly enough force to blanch the examiner’s nail bed. Each tender-point site should be palpated only once to avoid sensitization. The patient is asked to respond with a “yes” or “no” if he or she has pain at the site being examined. If the patient’s response is “yes,” the individual is asked to rate the pain on a scale of 0 (no pain) to 10 (worst pain), and record each response. A pain severity score of at least 2 is required to count a tender point as positive.
Pain scores from each of the 18 tender-point sites can be averaged to yield a Fibromyalgia Intensity Score (FIS) that varies from 0-10, with higher scores indicating more severe tenderness. The FIS can be monitored over time to evaluate response to therapy.
It is important to emphasize that pain upon light pressure may not be restricted to specific tender points. Many patients feel pain virtually anywhere that pressure is applied, including at the control points (eg, forehead, thumbnail, and distal right forearm) that are relatively insensitive to pain in healthy patients. Pain to palpation at control points should not be considered abnormal in fibromyalgia patients and should not be taken as proof that the patient is “faking” the examination.
The standard 18 fibromyalgia tender points exist as 9 pairs (in addition to 3 control sites; see below), 4 on the anterior of the body and 5 on the posterior of the body.  The sites are as follows:
1 (control site) – Forehead
2 and 3 (diagnostic sites) – Occiput at the nuchal ridge
4 and 5 (diagnostic sites) – Trapezius
6 and 7 (diagnostic sites) – Supraspinatus
8 and 9 (diagnostic sites) – Gluteal
10 and 11 (diagnostic sites) – Low cervical
12 and 13 (diagnostic sites) – Second rib
14 and 15 (diagnostic sites) – Lateral epicondyle
16 (control site) – Distal middle third of the right forearm
17 (control site) – Nail of the left thumb
18 and 19 (diagnostic sites) – Greater trochanter
20 and 21 (diagnostic sites) – Medial knee
The American College of Rheumatology (ACR) specifies the location of tender points on the anterior body as follows:
At the fifth through seventh inter-transverse spaces of the cervical spine
In the pectoral muscle, at the second costochondral junctions
Approximately 3 finger breadths (2 cm) below the lateral epicondyle
At the medial fat pad, proximal to the joint line
The ACR specifies the location of tender points on the posterior body as follows:
At the upper border of the shoulder in the trapezius muscle, midway from the neck to the shoulder joint
At the craniomedial border of the scapula, at the origin of the supraspinatus
In the upper outer quadrant of the gluteus medius
Just posterior to the prominence of the greater trochanter at the piriformis insertion
A useful device for rough quantitation of pain perception and pain tolerance is a pressure algometer, or dolorimeter, as depicted in the image below. Pressure algometry (dolorimetry) provides a simple determination of pressure pain thresholds at 4 tender points associated with fibromyalgia (ie, both lateral epicondyles, midpoints of the trapezii). Normal values are 4 kg/cm2 or greater.
Pressure algometry can also serve as a useful tool for educating the patient regarding the nature of altered central nociceptive processing, allodynia (pain with stimuli that should not cause pain, such as gentle touching) and hyperalgesia (amplification of pain experienced from peripheral stimuli that are expected to be painful). On follow-up visits, it can provide a semi-quantitative guide to therapy
After completing the tender-point examination, the physician should include neurologic, joint, and musculoskeletal evaluations, as follows:
- Check the joints for swelling, deformities, and erythema
- Examine the patient’s gait, joint range of motion (ROM), and posture for structural asymmetry and skeletal deficiencies
- Palpate the soft issues for tone or spasm
2016 update of Fibro Diagnosis criteria
Against 1990 and clinical criteria, the median sensitivity and specificity of the 2010/2011 criteria were 86% and 90%, respectively. The 2010/2011 criteria led to misclassification when applied to regional pain syndromes, but when a modified widespread pain criterion (the “generalized pain criterion”) was added misclassification was eliminated. Based on the above data and clinic usage data, we developed a (2016) revision to the 2010/2011 fibromyalgia criteria. Fibromyalgia may now be diagnosed in adults when all of the following criteria are met:
Generalized pain, defined as pain in at least 4 of 5 regions, is present.
Symptoms have been present at a similar level for at least 3 months.
Widespread pain index (WPI) ≥ 7 and symptom severity scale (SSS) score ≥ 5 OR WPI of 4–6 and SSS score ≥ 9.
A diagnosis of fibromyalgia is valid irrespective of other diagnoses. A diagnosis of fibromyalgia does not exclude the presence of other clinically important illnesses.
The fibromyalgia criteria have good sensitivity and specificity. This revision combines physician and questionnaire criteria, minimizes misclassification of regional pain disorders, and eliminates the previously confusing recommendation regarding diagnostic exclusions. The physician-based criteria are valid for individual patient diagnosis. The self-report version of the criteria is not valid for clinical diagnosis in individual patients but is valid for research studies. These changes allow the criteria to function as diagnostic criteria, while still being useful for classification.
2016 Revisions to the 2010/2011 fibromyalgia diagnostic criteria
Frederick Wolfe,Daniel J. Clauw,Mary-Ann Fitzcharles,Don L. Goldenberg,Winfried Häuser,Robert L. Katz,Philip J. Mease,Anthony S. Russell,Irwin Jon Russell,Brian Walitt
Seminars in Arthritis and Rheumatism
“Fibromyalgia” is basically widespread chronic pain without a known cause, the ultimate non-diagnosis. Some people will eventually discover a specific cause — there are many surprising causes of pain that can get overlooked for years at a time — but many never find out what’s going on.
More precisely now: fibromyalgia is a label for a pattern of unexplained stubborn chronic pain, stiffness, fatigue, and mental fog; it is a diagnosis of exclusion, [Wikipedia] used when all other known possibilities have been eliminated. It often goes with conditions like irritable bowel syndrome, migraines, and mood disorders. About 1–2% of the population suffer from this.1 Some people do get better, but most do not.
Controversy, stigma, and quackery swirl around fibromyalgia like a bad smell. It is often not diagnosed when it should be, and even more often these days it is diagnosed when it shouldn’t be.2 No medical speciality specializes in it. Rheumatologists and neurologists often get “stuck” with fibromyalgia patients, but have no idea what to do with them unless they’ve taken a special interest in the topic, and few do. There is no medical consensus on how fibromyalgia should be treated.3 Alternative medicine has rushed into the medical gap with a dizzying array of crackpot cures.
The biology of fibromyalgia remains a mystery. There are intriguing theories only. Many professionals still assume it’s a psychogenic problem (much like migraines were until surprisingly recently). Many others now believe that fibromyalgia is a disease of neurological sensitization — an overactive alarm system — but this is unproven and awkwardly at odds with some of what we do know about the condition. It’s likely that there are multiple causes. We just don’t know what’s going on with these patients, even though fibromyalgia research is booming — because a large percentage of it is worthless.
After a thorough history,your Doctor will try to eliminate any related conditions that may explain your pain symptoms.
To finally rule out Fibromyagia, your MD will conduct the WPI to verify if you meet the four criteria of the ACR.
Below is the WPI used by the ACR as a prelimerary Diagnostic Criteria for Fibromyalgia.
The form is present left to right in both rows.