Fibromyalgia affects millions of people nationwide, but very little is known about the nature of the disease, and the cause has not been determined. Doctors have no definitive way to diagnose it, nor has a cure been discovered. Here is a guide to understanding fibromyalgia:

Researchers believe five million Americans have fibromyalgia, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Fibromyalgia is marked by widespread physical pain that causes insomnia and extreme fatigue. People with fibromyalgia feel pain throughout their muscles, but the problem appears to originate with the central nervous system and its means of processing pain. Nearly nine out of 10 people diagnosed with fibromyalgia are women, according to NIAMS.

The symptoms of fibromyalgia are localized painful areas called tender points — sore spots in the soft tissue on the neck, shoulders, chest, lower back, hips, shins and joints. Pain typically radiates from this area, and it can be characterized as a deep ache or burning pain. While the pain may feel akin to arthritis, a physical exam should show that the joints are not directly affected by fibromyalgia because it is a neurological disease. Additional symptoms can include stiffness, headaches, painful menstrual periods or tingling and numbness in the hands and feet. Fibromyalgia can also result in non-muscular symptoms, including severe tiredness and trouble concentrating or learning new information — an impaired mental state referred to as “fibrofog.” The pervasive pain of fibromyalgia can cause secondary symptoms, such as difficulty sleeping or depression, which in turn exacerbate pain and fatigue.

Fibromyalgia has no known single cause, but NIAMS says researchers have a few prime suspects. This neurological condition could be triggered by emotional or physically traumatic events, and it has been linked to post-traumatic stress disorder (PTSD). Researchers believe there is a genetic component as well because a family history of fibromyalgia can increase the risk of developing the disease. Underlying physical conditions, such as head injuries or certain viral infections, may also induce fibromyalgia. While researchers have linked the illness to all of these potential causes, fibromyalgia can still simply appear on its own.

In part because so little is known about fibromyalgia, there is currently no known cure. However, available treatment programs could possibly help to alleviate the symptoms of ongoing pain. Treatment may include a combination of medication and exercise. An appropriate fitness program could consist of an exercise routine, physical therapy or light massages. A health care specialist should tailor the medication regimen to each individual patient’s needs, adjusting the treatment when necessary. Medication options include: anti-seizure drugs, antidepressants, muscle relaxants or sleeping aids. To find more information regarding treatment, visit the Fibromyalgia Information Foundation. Fibromyalgia poses a great number of challenges to daily life. For many people with fibromyalgia, the pain and fatigue can feel both overwhelming and debilitating, but psychotherapy may help an individual cope.