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Synonyms of Fibromyalgia

Disorder Subdivisions

General Discussion

Fibromyalgia is a chronic disorder characterized by pain throughout much of the body. The pain may begin gradually or have a sudden onset. Other symptoms are muscle spasms, fatigue, muscle tissue stiffness and non- restorative (unrefreshing) sleep. The exact cause of this disorder is unknown.

The terms Fibrositis, Fibromyositis, Periarticular Fibrositis and Rheumatoid Myositis are still being used by many to describe this condition. The ending of "itis" on each of these terms is actually incorrect. "Itis" means inflammation, and there is no inflammation in Fibromyalgia. The term Fibromyalgia has now become the accepted term, but many people continue to be diagnosed with the other synonyms. Tension Myalgia is another synonym that is currently being used.


Patients with Fibromyalgia may have a gradual or sudden onset of symptoms. The major symptom of this disorder is muscular pain. Areas which are frequently affected may include muscles in the back of the neck and shoulders, in the low back, the sides of the breast bone, and the bony points of the elbows, hips and knees. In addition, small specific areas called tender points, which are painful when pressure is applied, will be found by an examining physician.

Other symptoms found in most patients with Fibromyalgia are: muscle spasms, fatigue, muscle stiffness and non-restorative (unrefreshing) sleep.

Some patients with fibromyalgia may have chest pain, painful menstrual periods, difficulty concentrating, headaches, painful and/or frequent urination, diarrhea, constipation, numbness, dryness in the eyes and mouth, dizziness, swelling of a tendon (tendinitis), swelling of the connective tissue structure surrounding a joint (bursitis), depression and/or anxiety.


The exact cause of Fibromyalgia is not known. Researchers are studying serotonin, a chemical in the brain (neurotransmitter), to see if there is a disturbance in the messages sent between various parts of the central nervous system in people with Fibromyalgia. An imbalance of serotonin could have a hand in the increase of pain, depression and unrefreshing sleep associated with Fibromyalgia.

Muscle tissue, hormonal and immunological influences, as well as the possibility of a virus triggering the disorder are all being investigated by researchers.

Affected Populations

Fibromyalgia is diagnosed more frequently in females than in males. The majority of patients with this disorder will develop symptoms between the ages of 20 and 50 years. It is estimated that 3.7 million Americans are affected by Fibromyalgia.

Fibromyalgia may also develop in children and teenagers, often being misdiagnosed as "growing pains."

Related Disorders

Symptoms of the following disorders can be similar to those of Fibromyalgia. Comparisons may be useful for a differential diagnosis:

Chronic Fatigue Syndrome (CFS) is a disorder characterized by profound fatigue and other related symptoms. Standards for the diagnosis of CFS have been defined by researchers and the Centers for Disease Control (CDC). These include excessive fatigue or easy fatigability that does not respond to bed rest. The fatigue is severe enough to reduce the average daily activities of the affected individual by at least fifty percent. The onset of these symptoms is usually sudden, sometimes following a flu-like illness. According to the CDC, the profound fatigue must last for at least six months in order for the diagnosis to be made. Scientists believe Chronic Fatigue Syndrome is not contagious and laboratory tests (blood, urine, etc.) are of little value in diagnosing the syndrome. (For more information on this disorder, choose "Chronic Fatigue Syndrome" as your search term in the Rare Disease Database.)

Polymyalgia Rheumatica is a disorder characterized by pain and stiffness in certain muscle groups without causing permanent weakness or atrophy. The major symptoms of this disorder are pain and stiffness in the neck, shoulders, upper arms, lower back, hips and thighs. The symptoms often appear suddenly and the stiffness is most severe in the morning. The pain of PMR is felt on both sides of the body. Fever, lack of appetite, fatigue, weight loss and depression may also be present. (For more information on this disorder, choose "Polymyalgia" as your search term in the Rare Disease Database.)

Polymyositis is a systemic connective tissue disorder characterized by inflammatory and degenerative changes in the muscles, leading to weakness and some degree of muscle atrophy. The areas principally affected are the hip, shoulders, arms, pharynx and neck. Other symptoms of Polymyositis may include fever, weight loss and occasional pain or tenderness in muscles or joints. The exact cause of this disorder is not known. (For more information on this disorder, choose "Polymyositis" as your search term in the Rare Disease Database.)

Rheumatoid Arthritis is an inflammatory autoimmune disease in which the body's natural defenses against foreign agents (antibodies & lymphocytes) attack healthy joints. This disorder is characterized by a lack of appetite, fatigue, painful and deformed joints, early morning stiffness chiefly in the hands, knees, feet, jaw and spine. (For more information on this disorder, choose "Arthritis" as your search term in the Rare Disease Database.)

Sjögren Syndrome is a degeneration of the mucous secreting glands, particularly the tear and saliva glands. It is sometimes associated with arthritis. There is often a gritty, burning sensation in the eyes due to the loss of lubrication. When the mouth becomes dry, chewing and swallowing food is difficult. The lack of saliva causes particles of food to stick to the cheeks, gums and throat. Other symptoms of Sjögren Syndrome include a weak voice, dental decay, sensitivity of the eyes to the light, swelling of the salivary glands, and dryness of the nose, skin and vagina. Fibromyalgia may occur in conjunction with Sjögren's Syndrome. (For more information on this disorder choose "Sjögren" as your search term in the Rare Disease Database.)

Temporomandibular Joint Dysfunction (TMJ) is a painful disorder of the jaw joint which is made worse during or after eating or yawning. This disorder may cause limited jaw movement and clicks and pops during chewing. In severe cases pain may radiate into the neck, shoulders and back, mimicking the pain of Fibromyalgia. (For more information on this disorder choose "Temporomandibular Joint Dysfunction" as your search term in the Rare Disease Database.)

Standard Therapies

Fibromyalgia may be treated with low doses of tricyclic antidepressant medications. Amitriptyline (Elavil) and Cyclobenzaprine (Flexeril), which are prescribed as muscle relaxants, may be helpful. They may also help patients who suffer from unrefreshing (non-restorative) sleep. The tricyclic antidepressant amitriptyline (Elavil) can also be used to help patients with this disorder who have depression. When Elavil is used for this reason, it is given at higher doses.

Some patients receive temporary relief with stretching exercises, deep heat treatments, warm showers and baths, whirlpool baths and hot tubs, heating pads, massages, ice packs, acupuncture, biofeedback and/or aerobic exercise.

Investigational Therapies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:

Fibromyalgia Resources

NORD Member Organizations:

(To become a member of NORD, an organization must meet established criteria and be approved by the NORD Board of Directors. If you're interested in becoming a member, please contact Susan Olivo, Membership Manager, at solivo@rarediseases.org.)

Other Organizations:


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Report last updated: 2008/03/24 00:00:00 GMT+0