Fibromyalgia is a chronic condition that causes widespread pain and fatigue throughout the body, affecting millions of people worldwide and often leaving them searching for ways to manage symptoms that can feel overwhelming and unpredictable.

Epidemiology

Fibromyalgia is more common than many people realize. Around 4 million adults in the United States are living with this condition, which represents approximately 2 to 4% of the general population^[1][2][3]. Some research suggests that worldwide, about 5% of the population lives with fibromyalgia^[6]. The condition can develop at any age, including in children, though it typically appears between the ages of 25 and 55, with the average age of diagnosis falling between 35 and 45 years old^[2][8].

Women are significantly more affected by fibromyalgia than men. Studies show that women are twice as likely to experience fibromyalgia compared to men, and they account for 80 to 90% of all diagnosed cases^[2][8]. People older than 40 are more likely to develop the condition, though this does not mean younger individuals are immune^[2].

One of the challenges with fibromyalgia is that it is commonly either undiagnosed or misdiagnosed^[8]. Some estimates suggest that nearly 1 in 20 people may be affected by fibromyalgia to some degree, though exact figures remain unclear because diagnosing the condition can be difficult^[7]. There is no specific test that can confirm fibromyalgia, and its symptoms often overlap with other health problems, which adds to the confusion and delays in diagnosis.

Causes

The exact cause of fibromyalgia remains unknown, which can be frustrating for both patients and healthcare providers. However, researchers believe the condition is related to how the brain and spinal cord process pain signals^[1][7]. In people with fibromyalgia, the nervous system appears to amplify pain signals, making normal sensations feel more painful than they should. This phenomenon is known as central sensitization, which refers to changes in the central nervous system’s ability to process pain^[5][6].

Brain imaging studies have shown that people with fibromyalgia have an amplified pain response compared to those without the condition^[5]. Essentially, the pain is very real, but the cause is not damage to tissues or organs—it is an overprotective and overly sensitive nervous system. Research also suggests that certain brain chemicals, such as serotonin and norepinephrine (chemical messengers that help control pain, mood, and sleep), may be out of balance in people with fibromyalgia^[3].

Genetics appear to play a role as well. Fibromyalgia tends to run in families, which suggests that certain inherited genes might make some people more susceptible to developing the disorder^[2][6]. Studies have found a link between biological parents who have fibromyalgia and their children, and researchers estimate that around 50% of fibromyalgia risk can be explained by genetics^[6]. Genetic mutations in the genes responsible for forming neurotransmitters—the chemicals that send pain signals between the brain and body—might contribute to the condition^[2].

Fibromyalgia is not an inflammatory or autoimmune disease, meaning it does not cause damage to joints, muscles, or organs^[3][8]. However, there is ongoing debate about whether fibromyalgia might involve the immune system, as some research has pointed to potential links, though more evidence is needed before it can be classified as an autoimmune condition^[6].

Risk Factors

Even though the exact cause of fibromyalgia is not fully understood, certain factors are known to increase the risk of developing the condition. Age is one such factor, as people older than 40 are more likely to develop fibromyalgia, though it can affect individuals at any stage of life, including children^[2]. Gender also plays a significant role, with women being twice as likely as men to experience fibromyalgia^[2].

People with other chronic health conditions are at higher risk of developing fibromyalgia. These conditions include osteoarthritis (a type of arthritis that causes joint pain and stiffness), depression, anxiety disorders, chronic back pain, and irritable bowel syndrome (a digestive condition that causes stomach pain and bloating)^[2][4]. Having a rheumatic disease—a health problem that affects joints, muscles, or bones—also increases the risk. Examples include lupus, rheumatoid arthritis, or ankylosing spondylitis^[8].

Certain life events and circumstances can trigger fibromyalgia in people who are already predisposed to it. Physical trauma, such as an injury or surgery, can act as a trigger^[1]. Infections, especially those that cause severe symptoms, have also been linked to the onset of fibromyalgia^[2]. Emotional stress is another known trigger, and while stress cannot be measured with a medical test, too much of it can significantly affect a person’s health and increase their risk of developing fibromyalgia^[2].

In some cases, symptoms of fibromyalgia build up gradually over time without any single identifiable event that triggered them^[1][6]. For many people, the condition starts spontaneously, without any obvious cause. However, when there is a triggering event—such as trauma, stress, or illness—these are considered triggers rather than root causes of the disease^[6].

Symptoms

Fibromyalgia causes a wide range of symptoms, and the experience can be different for each person. The two most common symptoms are widespread pain and extreme fatigue^[2][4]. The pain is often described as a constant dull ache that affects both sides of the body and occurs above and below the waist. To be considered widespread, the pain must be present in at least four out of five regions of the body, including the left and right upper regions (such as the shoulder, arm, or jaw), the left and right lower regions (such as the hip, buttock, or leg), and the central region (including the neck, back, chest, or stomach area)^[1][9].

Fatigue is another hallmark symptom. People with fibromyalgia often wake up tired, even after sleeping for a long time. This happens because pain frequently disrupts sleep, and many people with fibromyalgia also have other sleep disorders, such as restless legs syndrome (an uncomfortable sensation in the legs that creates an urge to move them) or sleep apnea (a condition where breathing repeatedly stops and starts during sleep)^[1][3].

Fibromyalgia can also cause thinking-related problems, often referred to as “fibro fog” or “brain fog.” This makes it harder to pay attention, concentrate, or remember things^[1][2][3]. Other physical symptoms include muscle stiffness, headaches or migraines, face and jaw pain (often related to temporomandibular joint disorders), digestive problems such as diarrhea or constipation, and bladder control issues^[2][3].

Mental and emotional symptoms are also common. Many people with fibromyalgia experience anxiety, depression, or feelings of frustration and worry^[1][2][7]. Fibromyalgia can also make people more sensitive to light, noise, smells, touch, and temperature^[4]. Some people report numbness or tingling in their arms and legs, as well as increased sensitivity to even slight pressure on muscles or around joints^[4][8].

The symptoms of fibromyalgia are changeable and unpredictable. They can come and go in periods called flare-ups, where symptoms suddenly become worse. At other times, symptoms may improve or feel less intense^[2][7]. The peaks and valleys between feeling good and experiencing a flare-up can feel overwhelming and exhausting for people living with the condition.

Prevention

Because the exact cause of fibromyalgia is not known, there is no guaranteed way to prevent it. However, understanding the risk factors and making certain lifestyle choices may help reduce the likelihood of developing the condition or lessen the severity of symptoms if fibromyalgia does develop.

Managing stress is one important factor. Since stress can trigger or worsen fibromyalgia symptoms, learning to identify stress triggers and practicing stress-reduction techniques—such as deep breathing, meditation, mindfulness, or relaxation exercises—may be beneficial^[16][18]. Regular physical activity is also important. Exercise has been shown to help reduce pain and improve overall health, and staying active may help the body better manage pain signals^[16].

Maintaining a healthy lifestyle that includes good sleep habits, a balanced diet, and regular exercise can also support overall well-being. Getting enough sleep is particularly important, as poor sleep can worsen both pain and fatigue^[16][18]. While these measures cannot guarantee prevention, they may help reduce the risk or make symptoms more manageable if fibromyalgia does occur.

Pathophysiology

The underlying problem in fibromyalgia is thought to involve abnormal pain processing by the central nervous system, which includes the brain and spinal cord^[3][5][6]. This abnormal processing is called central sensitization, and it causes the nervous system to become overly sensitive to pain signals. In people with fibromyalgia, the brain amplifies pain messages, making even mild sensations feel much more painful than they should. The pain is real, but it is not caused by damage or inflammation in the tissues—it is a result of the nervous system being overprotective and hypersensitive^[6].

Research involving brain imaging has demonstrated that people with fibromyalgia have an amplified response to pain compared to those without the condition^[5]. Functional brain scans show abnormal processing of pain signals in the brains of fibromyalgia patients. This altered communication between the brain and body is a key feature of the disease^[16].

Brain chemicals called neurotransmitters play a significant role in this process. Neurotransmitters are substances that carry messages between nerve cells in the brain and throughout the body. In fibromyalgia, certain neurotransmitters—such as serotonin, norepinephrine, and possibly others—may be out of balance^[3][16]. These chemicals control not only pain but also sleep, mood, and memory, which explains why fibromyalgia affects so many different aspects of a person’s health^[16].

Another factor that may contribute to fibromyalgia is the immune system. While fibromyalgia is not classified as an autoimmune disease, there is growing evidence that the immune system may be involved in some way. Some researchers believe that imbalances in the immune system could contribute to the condition, though more research is needed to fully understand this connection^[6].

Fibromyalgia does not cause inflammation or damage to muscles, joints, or organs. Laboratory tests, such as blood tests, and imaging studies, such as X-rays, typically come back normal in people with fibromyalgia^[3][5][8]. This can make the condition difficult to diagnose, as there is no physical evidence of disease on standard medical tests. However, the symptoms are very real and result from the way the nervous system processes and interprets pain signals.