Researchers believe that fibromyalgia is the result of over-stimulation of the nervous system. This is the body’s typical response to a trauma or accident. Fibromyalgia causes interference in the flow of the neurotransmitters from your brain and your body- which result in chronic pain and muscle spasms.
Since fibromyalgia also prevents you from getting into that deep sleep that your body needs, you do not have normal serotonin levels. Serotonin is a hormone that regulates your mood when your levels of serotonin are decreased, it causes interference in your body’s ability to heal itself, and can cause you to experience depression and fatigue.
Fibromyalgia has been linked to a dysfunctional autonomic nervous system. Your nervous system is made up of several different components. Your central nervous system is comprised of your spine. It is your body’s primary control center. Your peripheral nervous system is the connection between your central nervous system and your tissues and organs. Your autonomic nervous system includes your sympathetic and parasympathetic nervous systems. Your sympathetic nervous system is the one that is what controls the “fight or flight” response you feel when you get into potentially dangerous situations. The parasympathetic nervous system is responsible for lowering your heart rate and slowing down your muscles in order to preserve your energy.
Individuals with fibromyalgia find that their sympathetic nervous system is functioning at a much higher level and their parasympathetic nervous system is functioning at a much lower level. This means that individuals with fibromyalgia are always feeling that “fight or flight” response. There have been some studies that have shown that when individuals are in a sustained hyperactive state, it can cause them to have an increased heart rate whether they are standing or lying down. Several studies have proven that women suffering from fibromyalgia also suffer with severe dysfunction of their autonomic nervous system.
Autonomic Nervous System
Your autonomic nervous system is a vital part of your central nervous system, or CNS. It automatically works to get your body through daily life. Your autonomic nervous system works with the natural neurotransmitters and hormones in your body so that you can be sure your body is working properly. It is in control of several of your bodily organs as well as bodily systems. The autonomic nervous system has several responsibilities including the following:
- Body temperature regulation
- Bowel/bladder function maintenance
- Heart rate maintenance
Two Autonomic System Branches
As mentioned previously, your autonomic nervous system is comprised of two different parts, called branches. They work together by sending messages through the neurotransmitters in your body. The two branches are as follows:
- Sympathetic: this helps you respond to stressful conditions- such as emergencies.
- Parasympathetic: this is responsible for regulating your digestion process and sleep.
What are Neurotransmitters?
In order to be able to communicate with each other, these two branches of your autonomic nervous system use hormones, known as neurotransmitters. These neurotransmitters are vehicles that carry information between your brain and the rest of your body. When something happens that interferes with this communication, your autonomic nervous system can become very confused. There are a few specific neurotransmitters that are thought to be part of the cause of fibromyalgia. These are as follows:
Substance P: this is a neurotransmitter that is found to be present in your spinal fluid. It facilitates communication of pain sensations to your brain and your body. There have been several studies that have shown that individuals with fibromyalgia actually have around three times more of this neurotransmitter in their spinal fluid than healthy ones do. This results in an enhanced perception of pain, which can cause a typically mild stimulus extremely painful.
Endorphins: these neurotransmitters are secreted by your body as a reaction to physical stressors such as fear or exercise. These are considered to be a natural opioid and help your body to be able to deal with fatigue and pain. Beta-endorphin is a neurotransmitter that is very involved in suppression of pain. Individuals suffering from fibromyalgia usually only have about half of the levels of this neurotransmitter that healthy individuals do. This could be an explanation as to why fibromyalgia patients are always in so much pain.
Serotonin: this is a neurotransmitter that helps with regulation of your mood. Serotonin keeps you from becoming overly excited or extremely depressed. There have been numerous studies that report low levels of serotonin in the brains of individuals with fibromyalgia. These lowered levels of serotonin are linked to chronic headaches, depression, and anxiety. Antidepressants can be used to regulate these levels to alleviate the symptoms of fibromyalgia.
What are Hormones?
In addition to the neurotransmitters, your autonomic nervous system also relies heavily on hormones to contribute to specific bodily functions. Hormones are specialized chemicals that are secreted by glands in your body. They help to cause growth, assist with fertility, and a variety of other functions. The hormones that are necessary for the functioning of your autonomic nervous system are as follows:
Cortisol: this is a hormone that is secreted by the adrenal glands. Cortisol is released when your body feels threatened or under stress. It is commonly referred to as the “stress hormone.” In individuals with fibromyalgia, the levels of cortisol are abnormal. The bodies of individuals with fibromyalgia are in a constant stressed state, which means that their cortisol levels are much higher. This leaves them in a constantly drained, tired state.
Growth Hormone: this is a hormone that is released in your body during deep sleep and exercise. The primary function of this hormone is to facilitate muscle/tissue growth and metabolism. It facilitates the healing of injuries or wounds. Individuals with fibromyalgia have lowered levels of this hormone. Their autonomic nervous system just doesn’t trigger the release of enough of this hormone to repair their tissues and muscles. To add insult to injury- individuals with fibromyalgia don’t sleep enough- which also limits the release of this hormone.
Norepinephrine: this is a hormone that is controlled by your sympathetic nervous system and released by the adrenal gland. It controls responses such as an increased heart rate, muscle contraction, and sweating. Individuals with fibromyalgia have lowered levels of this hormone, which causes fatigue and pain.
Fibromyalgia Syndrome and Your Nervous System
Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs) for Chronic Pain