Fibromyalgia is a complex and often misunderstood condition characterized by widespread chronic pain, fatigue, and tenderness in muscles, joints, and soft tissues. The exact cause of fibromyalgia remains unknown, but research points to a combination of genetic, neurological, and environmental factors that together disrupt the way the body processes pain and stress.
At the core of fibromyalgia is a phenomenon called **central sensitization**, where the central nervous system (the brain and spinal cord) becomes overly sensitive and amplifies pain signals. This means that people with fibromyalgia experience pain more intensely and from stimuli that would not normally be painful. This heightened pain sensitivity is not due to tissue damage or inflammation alone but rather to how the nervous system processes pain signals.
Genetics play a significant role in fibromyalgia susceptibility. Studies suggest that up to half of the risk for developing fibromyalgia may be inherited. Specific gene variations related to neurotransmitters—chemicals in the brain that transmit signals—such as serotonin, dopamine, and catecholamines, are linked to fibromyalgia. These neurotransmitters regulate mood, pain perception, and stress responses. When their function is altered, it can lead to increased pain sensitivity and mood disorders like depression and anxiety, which often co-occur with fibromyalgia.
Environmental factors also contribute to the onset of fibromyalgia. Many people report that their symptoms began after a physical trauma, surgery, infection, or significant psychological stress. Stressful life events, including childhood adversity or post-traumatic stress disorder (PTSD), are strongly associated with fibromyalgia. While stress alone does not cause fibromyalgia, it can trigger changes in the nervous system and immune responses that promote chronic pain.
One theory suggests that fibromyalgia resembles a state called “sickness behavior,” a biological response seen in animals and humans when fighting infection or injury. This response includes fatigue, pain, and cognitive difficulties, which are also common in fibromyalgia. Chronic stress or trauma may push the body into this prolonged state, disrupting normal pain regulation and immune function.
Inflammation, particularly neuroinflammation (inflammation in the nervous system), is another important factor. Although fibromyalgia is not classified as an inflammatory disease like arthritis, elevated levels of pro-inflammatory molecules called cytokines have been found in people with fibromyalgia. These cytokines can affect nerve function and contribute to symptoms such as pain, fatigue, and mood disturbances. Brain imaging studies have shown increased activation of glial cells—immune cells in the brain—in fibromyalgia patients, indicating ongoing neuroinflammation.
Autonomic nervous system dysfunction is also implicated. This system controls involuntary bodily functions like heart rate, digestion, and breathing. In fibromyalgia, there is often an imbalance between the sympathetic nervous system (which triggers the “fight or flight” response) and the parasympathetic nervous system (which promotes relaxation). This imbalance can lead to symptoms such as irregular heart rate, digestive issues, and altered breathing patterns. Some research suggests that respiratory variability—how breathing rate and depth change—may be linked to fibromyalgia symptoms, possibly through this autonomic dysregulation.
Sleep disturbances are common in fibromyalgia and may both contribute to and result from the condition. Poor sleep quality can worsen pain sensitivity and fatigue, creating a vicious cycle. The exact mechanisms behind sleep problems in fibromyalgia are still being studied, but they likely involve disrupted brain chemistry and nervous system function.
In summary, fibromyalgia arises from a complex interplay of genetic predisposition, altered pain processing in the central nervous system, neuroinflammation, autonomic nervous system imbalance, and environmental triggers such as stress or trauma. These factors combine to create a state where the body’s normal pain regulation is disrupted, leading to chronic widespread pain and other symptoms. Because of this complexity
