When you have a debilitating illness that impacts all aspects of your life, it’s normal to ask “why?” When it comes to fibromyalgia (FMS), we’re constantly adding more and more pieces to the puzzle. While we don’t yet have a complete picture, we’re getting closer.
Experts are learning a lot about what leads to FMS, but they’re still not clear on why these things lead to FMS in some and not in others.
Many experts believe the condition is linked to a genetic predisposition, which could clear up that question.
Fibromyalgia is grouped into two categories: primary and secondary. Primary FMS is the most common and is also called “idiopathic” FMS, meaning it has an unknown cause. Secondary FMS is associated with other causes of chronic pain.
Suspected causes of primary FMS include abnormalities in the brain and hormones, chronic sleep disturbance, psychological and social effects, and muscle abnormalities. Research is also looking in multiple other directions, with varied success.
Studies show, with FMS, the parts of your central nervous system that deal with pain signals work differently from other people’s. This is called central sensitization.
Researchers know people with FMS can have numerous abnormalities in their hormonal, metabolic and brain-chemical activity, but they’re 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 FMS may have abnormalities in any of the following:
- Serotonin: low levels
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 FMS.
- Melatonin: low levels
Some studies show taking melatonin supplements can cut pain levels, improve sleep and help alleviate depression symptoms in people with FMS. However, other studies have shown little or no improvement.
- Norepinephrine & Dopamine: low levels
Low levels of norepinephrine can lead to loss of alertness, mental fog, depression, and apathy. Your body uses norepinephrine to create dopamine, and low dopamine results in muscle pain, further cognitive dysfunction, and movement-related problems (i.e., tremor, poor balance, clumsiness.)
- Glutamate & GABA: out of balance
Glutamate’s job is to get your brain cells riled up. It’s important for learning and other situations that require rapid thought. GABA’s job is to counter glutamate and calm your brain. In FMS, research shows that glutamate levels are too high in relation to GABA, which can lead to overstimulation and even death of brain cells.
- Stress hormones: low levels
Deficiencies in the stress hormones cortisol and norepinephrine make your body less able to cope with psychological or physical stress. (Physical stress includes infection or strenuous activity.)
- IGF-1 growth hormone: low levels
This hormone promotes bone and muscle growth. Low levels are related to problems with thinking, low energy, muscle weakness an intolerance to cold. This level may be a marker of FMS rather than a cause.
- Substance P: high levels
Substance P is a chemical messenger in the nervous system associated with pain perception. If you have too much, your brain gets too many pain signals. People with FMS can have up to three times the normal amount in their spinal fluid.
- Abnormal pain perception: high activity levels
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.
Sleep disturbances and fibromyalgia go hand and hand, and some experts believe sleep disturbances come first.