Fibromyalgia is a disorder that causes significant pain throughout the body. Many researchers believe it occurs when the body misinterprets signals sent through the spinal cord and processes them as painful, even when they are not. Fibromyalgia can overlap with rheumatoid arthritis (RA) and cause similar symptoms. As a result, the two may be mistaken for each other.

Here is what you need to know about RA and fibromyalgia, including their symptoms, how they are diagnosed, and their key similarities and differences.

What Is Fibromyalgia?

Rheumatoid arthritis is an inflammatory autoimmune condition in which the body’s immune system attacks the joints, resulting in pain, swelling, and deformity. Fibromyalgia, on the other hand, is neither an autoimmune disease, an inflammatory disease, nor an immune system problem. Instead, it seems to be a condition of the nervous system.

People with fibromyalgia experience greater sensitivity to signals from the nervous system. This causes the brain to interpret small pain signals — or even signals that are not pain — as being extra painful. Thus, people diagnosed with fibromyalgia may feel a lot of pain, even when they haven’t experienced anything that should cause it.

What Causes RA and Fibromyalgia?

Scientists are not sure exactly what causes fibromyalgia. The condition occurs twice as often in women than in men, according to the Centers for Disease Control and Prevention (CDC). People who have a family history of fibromyalgia are also at a higher risk — though it doesn’t appear to be directly inherited from parents.

Moreover, a person can develop fibromyalgia after experiencing:

• A serious or significant illness, such as viral infections
• An injury (particularly a traumatic one)
• Injuries caused by repeated stress

Having osteoarthritis, RA, or lupus is also a potential risk factor for fibromyalgia, according to Mayo Clinic.

Researchers aren’t sure why these brain and the spinal cord changes occur in some people but not in others. Some believe repeated nerve stimulation may boost the amount of chemicals in the brain that signal pain. Additionally, the brain may develop a memory of past pain, causing a person to experience unusually strong, painful reactions to signals that may or may not actually be painful.

RA occurs when the immune system attacks the body’s healthy tissues. As with fibromyalgia, scientists don’t fully understand the underlying biological processes that cause RA. However, they’ve identified several hereditary and environmental risk factors for the condition.

Also similar to fibromyalgia, RA is more likely to develop in someone who has a relative with the condition — though RA also isn’t an inherited disease. Research has shown that people with specific genetic markers are much more likely to be diagnosed with rheumatoid arthritis than those without those markers.

Like fibromyalgia, RA is more prevalent in women than in men, according to the CDC.

The Connection Between Fibromyalgia and Rheumatoid Arthritis

Research has found that people diagnosed with rheumatoid arthritis are more likely to develop fibromyalgia. The exact prevalence of the conditions occurring together is unknown. One study found that 17.1 percent of people with RA also qualified for a fibromyalgia diagnosis. Another study estimated this prevalence to be somewhere between 7.4 percent and 19.8 percent, while a third put it at 14.8 percent.

Simply having a diagnosis of RA seems to increase the chances of also being diagnosed with fibromyalgia. Being a female with rheumatoid arthritis makes a person even more likely to develop fibromyalgia, as well.

Symptoms of RA and Fibromyalgia

Rheumatoid arthritis and fibromyalgia both cause significant pain throughout the body, which would seemingly make it difficult to differentiate between them. However, there are some key differences. A trained professional should be able to distinguish between them with relative ease.

Common symptoms of fibromyalgia and RA that may overlap include:

• Fatigue
• Trouble sleeping (a wide range of sleep problems)
• Pain in and around the joints
• Pain that seems to come from an indistinct source, making you feel achy all over
• Symptoms that seem to flare up, then disappear for a while, only to return later

One difference is joint symptoms. People with RA often experience significant joint stiffness, sometimes for hours each day. While people with fibromyalgia may also be stiff, it usually loosens after less than an hour. Rheumatoid arthritis will often cause joint swelling, while fibromyalgia does not.

RA pain, at least initially, is usually focused around the joints in the hands, feet, wrists, and knees. Fibromyalgia pain tends to be more widespread pain, and it can be difficult to pinpoint where it’s coming from.

Unlike fibromyalgia, RA is a progressive condition, meaning it worsens over time. As it progresses, RA causes joint damage and joint changes that are visible through the skin, which fibromyalgia does not.

Diagnosing Fibromyalgia With RA

If you have been diagnosed with RA and suspect you may also have fibromyalgia, you should speak with your health care provider. Most doctors or rheumatologists begin diagnosing fibromyalgia by asking questions about your condition and symptoms. They’ll ask whether you’ve been experiencing widespread pain for more than three months. They will also ask you if an injury, accident, traumatic event, illness, or anything else preceded your pain. Finally, they will ask about your personal and family health histories.

Your doctors will likely proceed by testing your blood. They will be looking at your RA activity markers, like your erythrocyte sedimentation rate, to see if they have gotten worse. They’ll also look for markers for other rheumatic diseases that sometimes coexist with RA, like lupus or Sjögren’s syndrome. There are no blood tests or markers specific to fibromyalgia, but by looking at your blood, a doctor can eliminate other possible causes of the pain you’re experiencing.

Your health care team may also screen you for other health problems, including neurological conditions like multiple sclerosis, as these can also cause widespread pain. Finally, they will rule out mental health diagnoses, as some conditions, like anxiety and depression, can also cause pain. If you’ve recently been in an accident or suffered an injury, your doctor may examine that as well, either through a physical examination or imaging tests like X-rays.

Your doctor may also have you fill out questionnaires about your pain. Several of these have been proved to help distinguish between pain caused by RA and pain caused by fibromyalgia.

Treating RA and Fibromyalgia

People living with both fibromyalgia and RA will need to pursue treatment options for both conditions. Because they arise from different causes (immune dysfunction in RA and central nervous system problems in fibromyalgia), this will often involve pursuing two treatment tracks at the same time.

Some treatments, such as over-the-counter pain relievers like nonsteroidal anti-inflammatory drugs (NSAIDs), may overlap for both conditions. However, treating RA usually involves taking corticosteroids or treating chronic inflammation with disease-modifying antirheumatic drugs (DMARDs), biologic medications, and more. On the other hand, some people with fibromyalgia do well when they take antiepileptic medications or antidepressants.

Working with physical and occupational therapists can help with both fibromyalgia and RA. Other ways to manage your symptoms include:

• Exercising regularly
• Practicing mindfulness
• Talking with a therapist who understands chronic conditions and chronic pain
• Keeping your stress levels low

Treating RA and fibromyalgia together involves working closely with your rheumatologist and health care team. They will be able to determine the right treatments for you and help maintain or increase your overall quality of life.

Find Your Team

On myRAteam, the social network for people living with rheumatoid arthritis and their loved ones, you can share your experiences with RA, talk to other people who have started conversations, or answer questions about aspects of the condition that you’ve dealt with before. Once you get to know people on the site, you’ll have your own team to help you live well with RA.

Are you living with RA and wondering if you have fibromyalgia too? Are you wondering how to manage treatments for both of the conditions together? Share your story in the comments below or by posting on myRAteam.