Fibromyalgia and Chemical Imbalances

Learning about fibromyalgia syndrome (FMS) may remind you of a nested Babushka doll. When you remove the top of the largest painted doll, another smaller doll is found inside and inside that doll is yet another and so on. In the case of fibromyalgia, there are many symptoms and triggers involved, and researchers studying each one find yet more appearing in one guise or another as they delve deeper into the study of this syndrome. The conclusion is that many factors are at work when you have fibromyalgia, leading to a variety of interrelated symptoms that may be difficult to separate as to cause.

While not yet fully understood, one of the major characteristics of this syndrome that seems to be at play is associated with chemical and hormonal imbalances occurring within the body. While both the role and significance of these imbalances is not yet fully explored or understood, research has indicated that issues with chemical neurotransmitters may be the source of some of the fibromyalgia symptoms.

Understanding Neurotransmitters and Fibromyalgia

Neurotransmitters are chemical messengers. They transmit signals throughout the body including to the brain, where additional neurotransmitters continue to relay signals throughout the brain. Each type of neurotransmitter plays a specific role in controlling the various actions of the body. Among the most common neurotransmitters or neurotransmitter-like compounds are serotonin, dopamine, melatonin, epinepherine, norepinepherine and substance P. They each interact and perform specific duties affecting mood control, emotions, sleep regulation and cognitive function.[1] Some of these chemicals have been studied in relation to fibromyalgia.

Research has discovered that those with FMS are affected by abnormalities occurring within the mechanics of some the various neurotransmitters. As a result of these abnormalities, the whole body becomes over-sensitized to pain. The pain threshold is lowered dramatically resulting in what is called “central sensitization.” This is a secondary response to the biochemical alterations that are creating an abnormality in the central processing system. The increased pain sensitivity has been attributed to an imbalance of various neurotransmitters responsible for determining what some researchers call the “volume control” on the body’s processing of pain. Research has also found that this imbalance is often coupled with lower levels of inhibitory neurotransmitters in fibromyalgia patients compared to those without the syndrome.[2]

While questions remain about whether this specific abnormality is the cause of FMS or the result of pain and stress on the central nervous system (CNS), the fact remains that there are clear indications of abnormal chemical and hormonal levels in those individuals who have FMS.

Chemicals Reacting in Unexplained Ways

There are several important chemicals and hormones that act or react differently in an individual who has fibromyalgia. The neurotransmitter serotonin is a good example. The levels of this hormone neurotransmitter are lower than average in a person with fibromyalgia. Since serotonin is responsible for such things as your level of pain, digestion, sleep patterns, mental clarity and feelings of comfort, changes in the level will also impact your mood. In fact, low levels of this hormone are linked to such things as depression, migraine and irritable bowel syndrome (IBS). These health problems are commonly found among individuals who have FMS.

Of concern with those researching fibromyalgia is the relationship between levels of serotonin and pain control. Serotonin, a natural stimulant associated with the wake portion of the sleep-wake cycle, increases pain sensitivity tolerance of nerves, as well as heightening an individual’s consciousness of pain. This is accomplished through the manufacturing of a chemical messenger known as substance P. While those who have fibromyalgia have low levels of serotonin, they also often have high levels of the pain causing substance called substance P. In fact, an individual with FMS may have three times as much the normal quantity of substance P in their spinal fluid. What is also of particular interest is that not only do those with FMS exhibit lower levels of serotonin and higher levels of substance P, but they are also lacking in the contributory producer of serotonin – the amino acid tryptophan.

Yet, serotonin is not the only neurotransmitter that is found in abnormal levels among those with fibromyalgia. Melatonin is another naturally occurring neurotransmitter like compound found in low levels in those who have FMS. It is derived from serotonin and plays a role in the sleep portion of your sleep-wake patterns. In the evening, melatonin is released, which promotes sleepiness. Therefore, lower levels can result in poorer sleep cycles.

Hormonal Imbalances a Factor

Not only are your sleep patterns, digestion and moods affected by FMS, your ability to handle stress is affected. Certain hormones help you deal with stress physically and mentally. Among these are cortisol and norepinephrine. Those with fibromyalgia are found to have lower levels of these chemicals. The result is a decreased ability to cope with physical and/or psychological stress.

In addition, individuals who have fibromyalgia may exhibit low levels of the growth hormone IGF-1. The hormone IGF-1 is responsible for promoting the growth of your muscles and bones. When your body lacks a sufficient amount, the result can be intolerance to cold temperatures, slow thought processing, a weakness in your muscles and low energy levels. The nerve growth factor is actually four time higher in those individuals with fibromyalgia than those without and IGF-1 imbalance appears to be a factor.[3]

Human growth hormones (HGH) decrease when there is hypothalamic-pituitary adrenal (HPA) axis dysfunction, making this yet another chemical issue associated with fibromyalgia.[4] The dysfunction also results in reduced production of dehydroepiandrosterone (DHEA). This is a prohormone which can affect physical performance and memory functions. Furthermore, cortisol is negatively affected by the failure of the HPA axis to function normally. It is possible that chronic stress may be a factor in dysfunctional performance of the HPA axis, but it may also be exacerbated by improper sleep patterns and high pain levels.

The suppression of the HPA axis is commonly attributed to chronic stress. However, the suppression is also associated with high levels of pain and poor sleep patterns.

Complicated Chemical Interactions and Imbalances

Fibromyalgia is characterized by the abnormality of various chemical and hormonal transmitters. There are low levels of serotonin, decreased growth hormones and increased levels of substance P. New medication is being developed to address these problems. In fact, research indicates that increasing the levels of melatonin, for example, can help decrease the pain associated with fibromyalgia.[5]  Unfortunately, most of these hormones cannot be routinely tested for by your physician, and thus, are not helpful in making the diagnosis of fibromyalgia. These studies were completed by researchers using specialized labs to look for minute changes in hormone levels. In essence, there is still so much research that needs to be done to gain a better understanding of how chemical interactions and imbalances impact fibromyalgia.


[1] Stahl, SM (2009). “Fibromyalgia – Pathways and Neurotransmitters.” Human Psychopharmacology: Clinical and Experimental, 24 (Supplement S1):S11–S17.

[2] Schmidt-Wilcke, T; and Clauw, DJ (2011). “Fibromyalgia: From Pathophysiology to Therapy.” Nature Reviews Rheumatology, 7 (9):518-527.

[3] Weiss, LD; Weiss, JM; and Pobre, T (2010). Oxford American Handbook or Physical Medicine and Rehabilitation. Oxford: Oxford University Press.

[4] Iqbal, R;  Mughal, MS;  Arshad, N; and  Arshad M (2009). “Pathophysiology and Antioxidant Status of Patients with Fibromyalgia.” Rheumatology International, 31(2): 149-152.

[5] Hussain, S A-R; Al-Khalifa, II; Jasim, NA; and Gorial, FI (2011). “Adjuvant Use of Melatonin for Treatment of Fibromyalgia.” Journal of Pineal Research, 50(3): 267–271.

This article was originally published on July 11, 2012 and last revision and update of it was 9/7/2015