Q. My sister went through a nightmare of doctor visits before she finally found out she has fibromyalgia. Why did it take so long for a correct diagnosis?

What your sister endured is common. It’s not easy to diagnose fibromyalgia with just a laboratory test. Health care practitioners have to rely on symptoms to make a diagnosis.

Unfortunately, fibromyalgia symptoms can vary between its victims. To further complicate the diagnosis, fibromyalgia imitates rheumatoid arthritis, multiple sclerosis, lupus and many other conditions.

The word “fibromyalgia” comes from the Latin term for fibrous tissue (fibro) and the Greek terms for muscle (myo) and pain (algia). Fibromyalgia is not a disease.

It’s a syndrome, which is a group of symptoms without a single cause. It is characterized by widespread pain, tenderness and fatigue.

Other symptoms of fibromyalgia may include: cognitive difficulties (“fibro fog”); sleep disturbances; morning stiffness; headaches; irritable bowel syndrome; painful menstrual periods; numbness or tingling of the extremities; restless legs syndrome; and sensitivity to heat, cold, noises and lights.

About 5 million people in the United States have fibromyalgia.

More than 80 percent of those diagnosed with fibromyalgia are women. Most people are diagnosed during middle age.

While fibromyalgia is a chronic condition, it is not progressive. It is never fatal, and it will not cause damage to the joints, muscles, or internal organs. In many people, the condition does improve over time.

The causes of fibromyalgia haven’t been found. There is speculation that the syndrome may be caused by trauma or repetitive injuries.

According to one theory, people with fibromyalgia may have genes that cause them to react strongly to stimuli that most people would not perceive as painful.

The American College of Rheumatology has established criteria for diagnosing fibromyalgia.

The patient must have diffuse tenderness and a history of widespread pain lasting more than three months. Pain is considered to be widespread when it affects all four quadrants of the body.

Fibromyalgia can be difficult to treat. Treatment often requires your doctor, a physical therapist and other health care professionals. There are clinics that specialize in fibromyalgia.

Fibromyalgia can be treated with antidepressants, because antidepressants elevate the levels of chemicals in the brain that are associated not only with depression, but also with pain and fatigue. Increasing the levels of these chemicals can reduce pain in people who have fibromyalgia.

People with fibromyalgia also may benefit from a combination of physical and occupational therapy, from learning pain management and coping techniques, and from properly balancing rest and activity.

Some people with fibromyalgia also report success with massage, movement therapies, chiropractic treatments and acupuncture.

There are steps you can take to minimize the effects of fibromyalgia.

Getting enough sleep, exercising and making changes at work can all help.

For example, some people cut down the number of hours they work, switch to a less demanding job or adapt a current job.

You can also change your work environment. An occupational therapist can help you design a more comfortable workstation.

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