Fibromyalgia - a complex diagnosis

Fibromyalgia is a soft-tissue rheumatic disease that is associated with various non-specific symptoms. Since there is no biological test for fibromyalgia, diagnosis is often very difficult.

Veröffentlicht am

8.7.2024

Zuletzt aktualisiert am

9.7.2024

Fibromyalgia is a chronic pain disorder characterised by pain in various parts of the body. It is also known as fibromyalgia syndrome (FMS), generalised tendomyopathy or fibre-muscle pain.

Following estimates, in Germany 1.4-6.6% of the population suffer from fibromyalgia. It is a relatively common pain disorder.

Fibromyalgia is accompanied by various symptoms. Often, the cause cannot be explained, which makes the diagnosis very complex for those treating the patient. There is no simple fibromyalgia test.

In order to rule out other causes for the symptoms that occur, various medical specialities usually need to be consulted. These include pain therapy, psychosomatic, neurological, internal medicine, orthopaedic and rheumatological experts.

For those affected, the path to diagnosis is often very long and can be extremely stressful.

This article describes how fibromyalgia is diagnosed and what you can do to be proactive.

Fibromyalgia diagnosis

Fibromyalgia syndrome (FMS) can be accompanied by a variety of symptoms. The symptoms that occur are often not specific to fibromyalgia, but can also occur in other diseases.

For this reason, it is not enough to confirm the main symptoms. Other causes of the pain must also be ruled out in order to initiate the right treatment.

Initial evaluation & anamnesis

During the first consultation (initial evaluation) with the doctor, a detailed medical history is taken. An anamnesis is a systematic questioning of the patient's state of health, pain symptoms and other typical symptoms.

According to medical guidelines, the main symptoms of fibromyalgia include

  • Chronic pain in several parts of the body
  • Sleep disorders or non-restorative sleep
  • Fatigue or a tendency to exhaustion, which can occur physically and mentally or cognitively

It is important and helpful to carefully document any symptoms you experience in advance. You can use a diary or a digital application such as the Fimo Health App to do this. This helps doctors to understand the causes of symptoms based on data and can speed up the diagnosis process.

Standardised questionnaires can also be used to record the symptom complex. If fibromyalgia is suspected, the Widespread Pain Index (WPI) and the Symptom Severity Scale (SSS, SS scale) can be used.

Widespread Pain Index (WPI)

The WPI measures pain in different areas of the body. For this purpose, 19 areas of the body are identified. Each area of the body in which pain has occurred in the past 7 days is labelled and given a score. The WPI is the sum of all zones in which pain has occurred.

By scanning the body in a structured way, the WPI can also help to systematically document pain.

In combination with the symptom severity scale, the Widespread Pain Index is part of the diagnostic criteria for fibromyalgia.

Symptom Severity Scale (SSS, SS Scale)

The Symptom Severity Scale is used in the diagnosis of fibromyalgia. It provides information about the severity of symptoms that are considered for the diagnosis of fibromyalgia and is divided into two parts:

In the first part, the severity of symptoms

  • fatigue
  • non-restorative sleep and
  • difficulty concentrating

is assessed on a scale of 0-3. As with the WIP, the SSS is also based on the last 7 days.

In the second part, somatic symptoms such as headaches, pain or cramps in the lower abdomen and depression are also considered.

The total number of points is added together and also taken into account in the diagnosis.

The diagnostic criteria of the medical guidelines state that symptoms are indicative of fibromyalgia if

  1. WPI ≥ 7 and SSS ≥ 5 or WPI 4-6 and SSS ≥ 9
  2. generalised pain in 4 out of 5 regions
  3. symptoms have been present for ≥ 3 months

In principle, the diagnosis of fibromyalgia can be made independently of and in addition to other diagnoses. Nevertheless, further examinations are usually carried out to rule out other causes. This is important in order to create the optimal therapy.

Physical examination and blood tests for suspected fibromyalgia

In order to assess the symptoms holistically and rule out other causes, a complete physical examination and blood tests are carried out as part of the diagnosis.

Physical examination

A physical examination involves a direct examination of the patient by the doctor. To do this, the practitioner looks at the body region, palpates it or checks for pain. Listening or smelling can also provide clues to the diagnosis.

The physical examination also includes neurological and orthopaedic findings.

Neurological findings are results from neurological examinations. These cover the brain and nervous system. The aim is to rule out neurological causes such as trauma, multiple sclerosis or myasthenia gravis for any symptoms that occur.

Orthopaedic findings are the results of orthopaedic examinations. Orthopaedics deals with diseases of the musculoskeletal system. The musculoskeletal system includes bones, joints, muscles and tendons.

The aim is to rule out orthopaedic causes such as fractures, arthrosis or osteoporosis as the cause of symptoms.

A psychiatric or psychotherapeutic co-assessment can be useful in order to recognise any depression or somatoform disorder that may be present.

Blood tests

Blood tests can provide indications of illnesses or rule them out.

If fibromyalgia is suspected, laboratory blood analyses are used to rule out differential diagnoses. Differential diagnoses are diseases with similar or almost identical symptoms.

If fibromyalgia is suspected, at least the following blood values are usually determined:

  • Erythrocyte sedimentation rate (ESR)
    Also known as erythrocyte sedimentation rate (ESR), ESR is a screening test for suspected inflammatory conditions.
  • C-reactive protein (CRP)
    CPR is an inflammatory parameter that is elevated when inflammation is present.
  • CBC
    The CBC is the basic form of blood count. It provides information about the composition of the blood and the presence of irregular cells. It includes ten parameters that provide information about the general state of health.
  • Creatine kinase (CK)
    Creatine kinase is an enzyme that can indicate diseases of the heart muscle or skeletal muscles, for example. The CK value can also be elevated in the case of burns or intensive strength and endurance training.
  • Calcium
    As a laboratory value, calcium provides information about bone metabolism, kidney function and hormonal processes (endocrinological correlations).
  • TSH
    TSH is a thyroid hormone that provides information about thyroid health in the laboratory.
  • Calcidiol
    Calcidiol is a precursor of vitamin D3. It provides information about the body's supply of vitamin D.

If these blood values are abnormal, a cause other than fibromyalgia may explain the symptoms. This is because these blood values are not usually abnormal in fibromyalgia.

Which neurological, orthopaedic or psychiatric examinations are carried out is decided by the attending physicians on the basis of the patient's medical history and current symptoms.

Fibromyalgia is a chronic pain disorder whose causes are not yet fully scientifically understood. According to the current state of medical science, fibromyalgia is present when symptoms such as chronic pain, sleep disorders and fatigue cannot be explained by another cause.

To date, there is no definitive fibromyalgia test. The diagnosis is based on certain diagnostic criteria, such as the number of painful body regions in conjunction with other symptoms, taking into account the patient's medical history, physical examination and the exclusion of other diseases. Laboratory tests can be used to rule out other diseases with similar symptoms.

The older "tender point" system is no longer required for diagnosis, but is still sometimes used in practice.

[1] Häuser, W., Eich, W., Herrmann, M. et al. Fibromyalgia Syndrome—Classification, Diagnosis, and Treatment. Dtsch Arztebl Int 2009; 106(23): 383-91; DOI: 10.3238/arztebl.2009.0383

[2] Deutsche Gesellschaft für Schmerzmedizin. DGS-PraxisLeitfaden zur Fibromyalgie (Teil 1: Diagnose). abgerufen am 03.07.2024 unter https://www.dgschmerzmedizin.de/fileadmin/dgs/Dokumente/PDF_oeffentlich/DGS-PLF-Fibromyalgie-Teil-1-Diagnostik-V1.1.pdf

[3] Patientenversion der wissenschaftlichen Leitlinie „Definition, Ursachen, Diagnostik und Therapie des Fibromyalgiesyndroms“ abgerufen am 03.07.2024 unter https://register.awmf.org/assets/guidelines/145-004l_S3_Fibromyalgiesyndrom_2019-11_1-abgelaufen.pdf

[4] Neuer Praxisleitfaden zur Fibromyalgie. Abgerufen am 03.07.2024 unter https://www.aerzteblatt.de/nachrichten/140049/Neuer-Praxisleitfaden-zur-Fibromyalgie