Causes of Fibromyalgia

Experts are still learning about what causes fibromyalgia and why some people are more prone to this disorder of body-wide pain, fatigue, and other symptoms. Many experts believe the condition is linked to a genetic predisposition. Brain and hormonal abnormalities, sleep problems, or a triggering event, such as physical or emotional stress, are possible causes as well. It's likely that a combination of factors is what ends up causing fibromyalgia in certain individuals.

Brain and Hormonal Abnormalities

Studies show that, in people with fibromyalgia, the parts of the central nervous system that deal with pain signals work differently than they do for other people.

People with fibromyalgia can have numerous abnormalities in their hormonal, metabolic, and brain-chemical activity, but experts are not sure whether these are causes of fibromyalgia or the effect of pain and stress on the central nervous system. Some physical changes in the brain have been discovered as well.

People with fibromyalgia may have abnormalities in any of the following:

• Serotonin levels (low): Serotonin impacts your sleep cycle, pain level, and feelings of well-being. Low levels are linked to depression, migraine, and irritable bowel syndrome, all of which frequently occur in people with fibromyalgia.
• Melatonin levels (low): Some studies show taking melatonin supplements can cut pain levels, improve sleep, and help alleviate depression symptoms in people with fibromyalgia. However, other studies have shown little or no such improvement.
• Norepinephrine and dopamine levels (low): Low levels of norepinephrine can lead to loss of alertness, mental fog, depression, and apathy. Low dopamine results in muscle pain, further cognitive dysfunction, and movement-related problems (i.e., tremor, poor balance, clumsiness).
• Glutamate and GABA (out of balance): Glutamate's job is to get your brain cells excited. It's important for learning and other situations that require rapid thought. GABA's job is to counter glutamate and calm your brain. In fibromyalgia, research shows that glutamate levels are too high in relation to GABA, which can lead to overstimulation and affect chronic pain.
• Cortisol levels (low): Deficiencies in the stress hormone cortisol, released when your body is under stress, may contribute to fibromyalgia.
• Substance P levels (high): Substance P is a chemical messenger in the nervous system associated with pain perception. If you have too much, your brain gets excessive pain signals. People with FMS can have up to three times the normal amount in their spinal fluid.
• Abnormal pain perception levels (high activity): Some studies and brain scans suggest fibromyalgia patients have too much activity in the parts of the brain and central nervous system that process pain.

Researchers are working to understand what these abnormalities mean and how this knowledge can lead to treatments.

Chronic Sleep Disturbance

Sleep disturbances and fibromyalgia go hand-in-hand, and some experts believe sleep disturbances come first. People with fibromyalgia have higher-than-average rates of restless leg syndrome, periodic limb movement disorder (PLMD), and sleep-related breathing disorders such as sleep apnea.

Some sleep problems of fibromyalgia may be linked to levels of the nervous system chemicals serotonin and melatonin, which help regulate sleep-and-waking cycles.

Psychological and Physical Stress

According to studies, people with fibromyalgia are more likely than others to have experienced severe emotional and physical abuse. This suggests that post-traumatic stress disorder (PTSD) or chronic stress could play a strong role in the development of fibromyalgia in some people.

Physical stress can also cause fibromyalgia. Some possible triggers include an injury, giving birth, or having surgery.

Other Medical Conditions

Fibromyalgia can appear either after or in conjunction with other medical problems, especially those that affect the joints, muscles, and bones. These include:

• Ankylosing spondylitis
• Lyme disease
• Osteoarthritis
• Rheumatoid arthritis
• Lupus

A healthcare provider may test for these or other conditions when working to diagnose fibromyalgia.

Risk Factors

Despite some uncertainty surrounding causes of fibromyalgia, factors that seem to increase the statistical risk of developing the condition are more clear. These include:

• Sex assigned at birth: It's estimated that 75% to 90% of those who have it are people assigned female at birth.
• Age: Fibromyalgia is usually diagnosed between the ages of 20 and 50 years. You’re more likely to get it as you get older, and by age 80, about 8% of adults meet the criteria for fibromyalgia from the American College of Rheumatology.
• Family history: Your risk of developing fibromyalgia is about eight times higher if you have a first-degree relative with the condition.
• Obesity: A 2012 study found that patients who were obese with a body mass index (BMI) over 35 had higher levels of fibromyalgia symptoms.

A Word From Verywell

Your fibromyalgia may be caused by these or a combination of factors. Because no two cases are alike, talk to a healthcare provider about your possible causes and how to determine a treatment strategy that works for you.