Is Fibromyalgia an Autoimmune Disease?

Fibromyalgia has a lot of symptoms in common with autoimmune diseases. In fact, a lot of people mistakenly believe that it's classified as autoimmune. It's not--at least, not at the moment.

Fibromyalgia affects 2% to 4% of adults. Autoimmune diseases can, and frequently do, occur alongside it. Additionally, some autoimmune diseases, such as lupus, have symptoms that are strikingly similar to fibromyalgia.

Because fibromyalgia was once believed to be an arthritis-related condition, and many types of arthritis, such as rheumatoid arthritis (RA), are autoimmune diseases, the assumption used to be that fibromyalgia fit into this category. Research, though, has pointed in different directions.

However, we can't definitively say fibromyalgia isn't autoimmune since we still don't know the underlying cause(s) of the condition. It's possible that future studies may discover that autoimmunity plays a part in at least some cases.

Why Isn't Fibromyalgia an Autoimmune Disease?

Some research suggests that the immune system in fibromyalgia may tend to have some irregularities, such as being chronically overactive. Some people believe that means it's autoimmune, but in fact, these are two different types of immune dysfunction.

First, it's important to understand what autoimmunity is. In autoimmune disorders, the immune system mistakes a particular tissue or structure in the body for a dangerous invader, such as a virus or bacteria. It then attacks that tissue or structure in an attempt to destroy it. That process typically causes damage and inflammation at the site. (Inflammation is a normal and necessary part of the healing process, but it's a problem when it becomes chronic.)

However, emerging research may re-focus the attention back in that direction. It shows that certain nerve structures are sometimes damaged in fibromyalgia. So far, we don't know why or how prevalent this damage is. That means we don't yet know whether this is evidence of autoimmunity. It's certain to be looked at as one possible cause, though.

Triggers of Fibromyalgia

No particular trigger has been shown to spur the onset of fibromyalgia. Clinicians believe there are a variety of causes, including:

• Emotional trauma
• Viral infections
• Physical injuries

More and more, fibromyalgia is being called a neuro-immune disorder or a central sensitivity syndrome.

Brain Chemicals & Hormones

Fibromyalgia patients typically exhibit abnormalities in brain chemicals as well as hormonal abnormalities.

Brain chemical and hormonal imbalances that may occur in fibromyalgia include: 

• Reduced opioid receptor activity in the parts of your brain that regulate mood and the emotional aspects of pain
• Lower serotonin levels or activity
• Lower levels of the stress hormones norepinephrine and cortisol, which lead to inadequate responses to physical and psychological stresses
• Low levels of IFG-1, which promotes bone and muscle growth
• Up to three times the normal level of substance P, which is associated with increased pain perception

Other Common Symptoms of Fibromyalgia

As you now know, there is no singular pattern of symptoms for fibromyalgia. However, a group of symptoms is common in many patients and include:

• Aching, radiating, widespread pain and stiffness
• Pain from stimuli that don't normally cause pain (i.e., light pressure)
• Pain that moves from one part of the body to another and isn't associated with damage
• Sleep disorders (as overlapping conditions)
• Cognitive dysfunction (often called "fibro fog")
• Unrefreshing sleep that leads to extreme fatigue
• Restless leg syndrome (as an overlapping condition)
• Irritable bowel syndrome (as an overlapping condition)

Similar Diseases

RA and lupus are two autoimmune diseases that can have symptoms similar to fibromyalgia. Others may be similar as well, depending on the particular fibromyalgia symptoms a person has.

Additionally, people with fibromyalgia may have overlapping autoimmune disease(s). A correct diagnosis is important to an effective treatment plan.

RA and lupus, however, do have diagnostic markers, including inflammation and damage, that doctors can look for when making a diagnosis.

A Word From Verywell

We'll need a lot more research to determine whether fibromyalgia belongs in the autoimmune category. Until we know for sure, doctors are unlikely to prescribe common autoimmune treatments, such as drugs that suppress the immune system, for this condition.