What Is Fibromyalgia?

Fibromyalgia syndrome is a common and chronic disorder characterized by widespread muscle pain, fatigue, and multiple tender points. The word fibromyalgia comes from the Latin term for fibrous tissue (fibro) and the Greek ones for muscle (myo) and pain (algia). Tender points are specific places on the bodyon the neck, shoulders, back, hips, and upper and lower extremitieswhere people with fibromyalgia feel pain in response to slight pressure.

Although fibromyalgia is often considered an arthritis-related condition, it is not truly a form of arthritis (a disease of the joints) because it does not cause inflammation or damage to the joints, muscles, or other tissues. Like arthritis, however, fibromyalgia can cause significant pain and fatigue, and it can interfere with a person's ability to carry on daily activities. Also like arthritis, fibromyalgia is considered a rheumatic condition.

You may wonder what exactly rheumatic means. Even physicians do not always agree on whether a disease is considered rheumatic. If you look up the word in the dictionary, you'll find it comes from the Greek word rheum, which means fluxnot an explanation that gives you a better understanding. In medicine, however, the term rheumatic means a medical condition that impairs the joints and/or soft tissues and causes chronic pain.

In addition to pain and fatigue, people who have fibromyalgia may experience

• sleep disturbances,
• morning stiffness,
• headaches,
• irritable bowel syndrome,
• painful menstrual periods,
• numbness or tingling of the extremities,
• restless legs syndrome,
• temperature sensitivity,
• cognitive and memory problems (sometimes referred to as "fibro fog"), or
• a variety of other symptoms.

Fibromyalgia is a syndrome rather than a disease. Unlike a disease, which is a medical condition with a specific cause or causes and recognizable signs and symptoms, a syndrome is a collection of signs, symptoms, and medical problems that tend to occur together but are not related to a specific, identifiable cause.

Who Gets Fibromyalgia?

According to a paper published by the American College of Rheumatology (ACR), fibromyalgia affects 3 to 6 million - or as many as one in 50 - Americans. For unknown reasons, between 80 and 90 percent of those diagnosed with fibromyalgia are women; however, men and children also can be affected. Most people are diagnosed during middle age, although the symptoms often become present earlier in life.

People with certain rheumatic diseases, such as rheumatoid arthritis, systemic lupus erythematosus (commonly called lupus), or ankylosing spondylitis (spinal arthritis) may be more likely to have fibromyalgia, too.

Several studies indicate that women who have a family member with fibromyalgia are more likely to have fibromyalgia themselves, but the exact reason for thiswhether it be hereditary or caused by environmental factors or bothis unknown. One study supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) is trying to identify if certain genes predispose some people to fibromyalgia.

What Causes Fibromyalgia?

The causes of fibromyalgia are unknown, but there are probably a number of factors involved. Many people associate the development of fibromyalgia with a physically or emotionally stressful or traumatic event, such as an automobile accident. Some connect it to repetitive injuries. Others link it to an illness. People with rheumatoid arthritis and other autoimmune diseases, such as lupus, are particularly likely to develop fibromyalgia. For others, fibromyalgia seems to occur spontaneously.

Many researchers are examining other causes, including problems with how the central nervous system (the brain and spinal cord) processes pain.

Some scientists speculate that a person's genes may regulate the way his or her body processes painful stimuli. According to this theory, people with fibromyalgia may have a gene or genes that cause them to react strongly to stimuli that most people would not perceive as painful. However, those genesif they, in fact, existhave not been identified.

How Is Fibromyalgia Diagnosed?

Research shows that people with fibromyalgia typically see many doctors before receiving the diagnosis. One reason for this may be that pain and fatigue, the main symptoms of fibromyalgia, overlap with many other conditions. Therefore, doctors often have to rule out other potential causes of these symptoms before making a diagnosis of fibromyalgia. Another reason is that there are currently no diagnostic laboratory tests for fibromyalgia; standard laboratory tests fail to reveal a physiologic reason for pain. Because there is no generally accepted, objective test for fibromyalgia, some doctors unfortunately may conclude a patient's pain is not real, or they may tell the patient there is little they can do.

A doctor familiar with fibromyalgia, however, can make a diagnosis based on two criteria established by the ACR: a history of widespread pain lasting more than 3 months and the presence of tender points. Pain is considered to be widespread when it affects all four quadrants of the body; that is, you must have pain in both your right and left sides as well as above and below the waist to be diagnosed with fibromyalgia. The ACR also has designated 18 sites on the body as possible tender points. For a fibromyalgia diagnosis, a person must have 11 or more tender points. (See illustration on page 5.) One of these predesignated sites is considered a true tender point only if the person feels pain upon the application of 4 kilograms of pressure to the site. People who have fibromyalgia certainly may feel pain at other sites, too, but those 18 standard possible sites on the body are the criteria used for classification.