The main symptom of fibromyalgia is pain that is believed to derive from an increased sensitivity to pain stimuli. The pain can be brought on by different situations, including noises, weather changes, or stress, but it may also occur without any relation to external events. The characteristic pain usually affects the neck, buttocks, shoulders, arms, upper back, and chest. "Tender points" are localized areas of the body that are tender to light touch. The tender points of fibromyalgia are commonly located around the elbows, shoulders, knees, hips, back of the head, and the sides of the breastbone.

Other common symptoms associated with fibromyalgia include

fatigue, malaise, or tiredness,
sleep disturbances,
migraine,
numbness or tingling in the hands and feet or various body parts, and
irritable bladder.

Irritable bladder can cause frequent urination and discomfort during urination (dysuria). Bowel disturbances as seen with irritable bowel syndrome may occur, including diarrhea and abdominal pain. Irritability, mood changes, depression, forgetfulness, nervousness, lack of concentration, and anxiety are emotional symptoms of fibromyalgia.

Causes of fibromyalgia

Genetics has been shown to play a role in the causation of fibromyalgia. While stress does not cause the condition, the symptoms often become evident after stressful events. These events may be emotional (such as a traumatic life event), physical (such as car accidents), or medical (for example, certain infections, illnesses, or conditions that cause chronic pain). The symptoms are thought to arise from an abnormality in the manner in which the brain and spinal cord process pain sensations. This results in a lower threshold at which stimuli cause pain or discomfort in people with fibromyalgia. Further, pain can be more intense because of abnormalities in the central nervous system and in pain processing.