Fibromyalgia and Rheumatoid Arthritis

Rheumatoid arthritis (RA) and fibromyalgia (FMS) are chronic pain conditions that commonly go together. Though RA is an autoimmune disease (in which your immune system attacks your joints) and FMS is primarily thought of as a neurological condition (in which pain signals are amplified), they have many of the same symptoms and are believed to have shared underpinnings as well.

Fatigue, cognitive dysfunction, and sleep problems are primary symptoms of both RA and FMS, which can make it hard for healthcare providers to diagnose them. When you have both, this process becomes even harder. Following through is still essential, though—you likely won't get the treatment you need to manage your illness(es) and remain as functional as possible without identifying exactly what they are.

How They're Linked

Researchers don't know the precise cause(s) of either condition or why fibromyalgia and rheumatoid arthritis are seen together in patients so often, but some theories have emerged. One thing that's become clear is that there's substantial overlap in risk factors and causal factors for these illnesses.

While any or all of these factors may contribute to the development of RA and FMS, these conditions can strike anyone at any age. Both conditions also have juvenile forms: juvenile idiopathic arthritis and juvenile fibromyalgia.

Age and Sex

Most cases of RA are diagnosed in people between the ages of 40 and 60. FMS skews younger, developing most often between 20 and 50.

Women develop these conditions more than men, accounting for about 75% of RA diagnoses and between 75% and 90% of FMS diagnoses.

Hormones

Sex hormones, especially estrogen, and hormonal events such as pregnancy and menopause are believed to play a role in the development of both conditions.

Genetics

Both conditions have a tendency to "cluster" in families, suggesting a genetic predisposition.

Some specific genes have been identified as potential causal factors; notably, genes for a part of the immune system called the human leukocyte antigen complex (HLA) may play a role in both RA and FMS. The specific HLA genes may not be the same in both conditions, though.

Infectious Agents

Exposure to certain infectious agents (i.e., viruses or bacteria) is suspected to alter some people's immune systems and trigger autoimmunity or other types of immune dysfunction (such as those seen in FMS).

While both conditions are tentatively linked to several different infectious agents, they both appear to be associated with the Epstein-Barr virus (EBV), which causes mononucleosis (mono).

Lifestyle

Smoking cigarettes is tied to elevated risk and also more severe symptoms in both conditions.

Higher body weight is associated with an elevated risk and may also exacerbate symptoms of both illnesses.

Which Comes First?

While the list of causes and risk factors seems to paint a picture of two diseases with multiple common causes, if that were the whole picture, people with FMS would develop RA at about the same rate as those with RA developed FMS. This is not the case.

In fact, it appears that people with a wide array of chronic-pain conditions develop FMS at a high rate. Some scientists believe that's because chronic pain, from RA or other sources, can cause changes in the way the nervous system perceives and processes pain, and that that process can trigger FMS.

This idea is supported by a study published in Arthritis Care & Research, which demonstrates how people with RA can develop high levels of pain sensitization (an exaggerated physical response to pain)—a known feature of FMS.

Not everyone with chronic pain will develop FMS, though. The common causes and risk factors outlined above, therefore, probably play a role.

Symptoms

While symptoms of RA and symptoms of FMS can be extremely similar, each has additional symptoms that aren't seen in the other.

For example, pain is involved in both RA and FMS, but the types of pain differ. RA can impact any joint and even your organs, but it most often involves the small joints of the hands and feet. FMS pain can strike anywhere, but it's widespread by definition, and it's more common along the spine than in the extremities.

In both cases, however, pain is in the same place on both sides of the body.

Cognitive dysfunction—including problems with short-term memory, multi-tasking, communication, and spatial awareness—is so characteristic of FMS that it has been nicknamed "fibro fog." This is not a symptom of RA.

Compounding Effects

Regardless of why you have both conditions, they can make each other worse. The pain of RA can trigger FMS flares and make your symptoms harder to control, and FMS amplifies the pain of RA.

In people with both, a 2017 study shows that FMS is not only especially common in people with RA, it also has a major impact on your quality of life. That finding is backed by another study published the same year in Rheumatology and Therapy, which found that FMS had a bigger impact on participants' global assessment of RA than any other latent factor.

If you're diagnosed with only one of these conditions but have symptoms that could indicate the other, make sure to bring it up with your healthcare provider.

Impact and Progression

These two conditions have some striking differences when it comes to what's going on in your body and how they progress.

RA is an autoimmune disease. FMS isn't currently classified as autoimmune, although research suggests that some cases may involve autoimmunity. Even so, the pain of FMS is felt in the muscles and connective tissues and comes from the nervous system, whereas the pain of RA comes from inflammation and joint damage.

Perhaps the most notable difference is that RA causes damage and deformity in your joints. FMS is not linked to any joint damage, deformity, or deterioration.

The Disease Course

The course of RA is unpredictable, but most cases are progressive. After many years (or without treatment), some people with RA develop painful and debilitating deformities to the hands and feet. The larger joints, such as the hips and knees, can become severely impacted and make walking difficult or impossible.

It's common for people to believe that someone with RA will always end up in a wheelchair, but this is a myth. With proper treatment, that's far rarer than you might expect. Even so, RA can cause structural damage that imposes limits on movement and mobility.

FMS is also unpredictable. Research suggests that nearly half of people with the condition will make a significant improvement over a three-year period, and about two-thirds will improve over a 10-year period. So far, researchers don't know what factors influence the course of the illness.

FMS is debilitating in different ways that RA. Physical activity takes a high toll on people with fibromyalgia, intensifying all of their symptoms; a significant amount of rest is required for recovery. Fatigue is often extreme and isn't relieved by sleep.

Cognitive dysfunction alone makes it impossible for some people to do their jobs.

Flares and Remissions

Some cases of RA have prolonged remissions in which symptoms vanish for several years. Others have periodic flares (when symptoms are more severe) and remissions (periods of lighter symptoms). The majority, however, have a chronic, progressive form of RA.

FMS typically involves flares and remissions as well, but a small minority of cases involve more or less consistent symptom levels. Long-term remissions are rare but possible.

Getting a Diagnosis

When you go to the healthcare provider with pain that could be due to rheumatoid arthritis, fibromyalgia, or something with a similar presentation, your healthcare provider will likely start by listening to your symptoms, asking about your medical and family history, and performing a physical exam.

No single blood test can diagnose either condition, so healthcare providers look at multiple test results to get the total picture of what's going on. They'll likely order several tests to look for markers of inflammation in your blood, such as:

• Complete blood count (CBC)
• Erythrocyte sedimentation rate (ESR or sed rate)
• C-reactive protein (CRP)

Know, though, that even with testing, nailing down a diagnosis can take some time.

High Inflammatory Markers

FMS doesn't involve high levels of inflammation. RA does, so high levels of inflammatory markers are a good indication that you have something inflammatory and possibly autoimmune.

From there, your healthcare provider may order blood tests for specific autoantibodies depending on which conditions they believe are likely. Antibodies for RA include:

• Anti-cyclic citrullination peptide (anti-CCP): This autoantibody is found almost exclusively in people with RA and is present in between 60% and 80% of them.
• Rheumatoid factor (RF): This antibody is indicative of RA and is found in about 70% to 80% of people who have it.

Your healthcare provider may also order several other blood tests, imaging tests such as X-rays and magnetic resonance imaging (MRI) to confirm the diagnosis and get an idea of how the disease may progress.

Low or Normal Inflammatory Markers

If inflammatory markers are low or in the normal range, it can help point to an FMS diagnosis, which is a diagnosis of exclusion. Depending on your symptoms, your healthcare provider may order more blood tests or imaging to rule things out.

Once other possible causes of your symptoms are eliminated, your healthcare provider can confirm an FMS diagnosis in two ways: a tender-point exam or scores on a specially designed evaluation.

Treatments

Given the type of diseases these are, their treatments differ.

Managing RA

There are many drugs available for treating RA. They include:

• Disease-modifying antirheumatic drugs (DMARDs): Trexall/Rheumatrex (methotrexate), Imuran (azathioprine), and Azulfidine (sulfasalazine)
• TNF blockers/Biologics/Biosimilars: Enbrel (etanercept), Remicade (infliximab) and Humira (adalimumab)
• JAK Inhibitors: Xeljanz (tofacitinib), Olumiant (baricitinib), Rinvoq (upadacitinib)
• Glucocorticoids: Prednisone and methylprednisolone
• Non-steroidal anti-inflammatories (NSAIDs): Motrin/Advil (ibuprofen), Aleve (naproxen)
• COX-2 inhibitors (rare): Celebrex (celecoxib)

The treatment regimen may also include steroid injections, physical therapy, massage therapy, and lifestyle modifications.

Sometimes, surgery may be performed to help people with severe joint damage.

Managing Fibromyalgia

Common drugs for treating FMS include:

• Serotonin-norepinephrine reuptake inhibitors (SNRIs): Cymbalta (duloxetine), Savella (milnacipran)
• Anti-seizure drugs: Lyrica (pregabalin), Neurontin (gabapentin)
• Tricyclic antidepressants: amitriptyline
• Analgesic painkillers: Vicodin (hydrocodone acetaminophen), Oxycontin (oxydocone)
• Other medications: Xyrem (sodium oxybate), low-dose Naltrexone

Other common treatments include:

• Supplements
• Myofascial release
• Acupuncture
• A specially tailored, moderate exercise program
• CBD oil

Managing Both

If you're taking medications for both RA and FMS, be sure to talk to your healthcare provider and pharmacist about possible drug interactions.

Some FMS experts believe that the corticosteroids sometimes used to treat RA can make FMS symptoms worse; at the very least, they're ineffective against fibromyalgia symptoms.

By working closely with your healthcare provider, you should be able to find treatments that work for both of your conditions.

A Word From Verywell

Both RA and FMS can be limiting. By finding and following a treatment/management regimen, you may be able to preserve your functionality and independence.

Because both conditions can lead to depression and isolation, it's important for you to have a support system. Keep lines of communication open with your healthcare provider and the people you're close to, and get early help if you think you're becoming depressed. Support groups—both online and in your community—may be a big help to you, too.