• Spondylitis and fibromyalgia have some symptoms in common, which may complicate diagnosis.
• Imaging and blood tests can help distinguish spondylitis from fibromyalgia and provide an accurate diagnosis for earlier treatment.
• It is possible to have both spondylitis and fibromyalgia.

Fibromyalgia and spondylitis can have similar symptoms, and sometimes it’s difficult even for doctors to tell the difference. Both conditions can cause chronic pain and fatigue, leading to frequent misdiagnosis. As one MySpondylitisTeam shared, “I was diagnosed with fibromyalgia for 20 years by three different rheumatologists. Other specialists thought I had an autoimmune disease. I finally received my spondylitis diagnosis yesterday.”

In many cases, the location of the pain and the results of imaging or blood tests can help a doctor distinguish between the two. An accurate diagnosis is important so that appropriate treatment can start as early as possible.

It’s also possible to have both spondylitis and fibromyalgia. In fact, more than 3,500 members of MySpondylitisTeam report having both conditions. “It’s not bad enough we have spondylitis, but to top it off with fibromyalgia is a kicker. Pain, pain, pain,” one member wrote.

What Are Spondylitis and Fibromyalgia?

Spondylitis — also known as spondyloarthritis — is a type of inflammatory arthritis that is caused by immune dysfunction. There are various types of spondylitis. Axial spondyloarthritis (axSpA) affects the axial skeleton, which includes the spine, neck, ribs, and hips. Types of axSpa include radiographic axSpA — also called ankylosing spondylitis — which is visible on X-rays and other image scans. Another type is nonradiographic axSpA, which is not visible on X-rays but is seen on MRI. Symptoms of axSpA include lower back pain, hip pain, chest pain, joint damage, stiffness, and fatigue.

Peripheral spondyloarthritis affects other joints besides the hips and spine and includes psoriatic arthritis, enteropathic arthritis, and reactive arthritis.

Fibromyalgia, also known simply as fibro, is a musculoskeletal disease that causes widespread pain throughout the body. Other symptoms include:

• Muscle pain and stiffness
• Fatigue
• Sleeping problems
• Cognitive problems, often called brain fog
• Depression
• Anxiety

Scientists don’t fully understand the exact cause of fibromyalgia, but research indicates that the condition may be due to chemical imbalances that cause abnormal pain signaling in the brain.

Differences Between Spondylitis and Fibromyalgia

One key difference between spondylitis and fibromyalgia is the location of pain. Axial spondyloarthritis affects the spine and the sacroiliac joints that connect it to the pelvis. Pain from axSpA is most typically centered in the low back and hips.

Fibromyalgia is characterized by widespread pain that can affect much of the body. However, widespread pain can also be a symptom of axSpA, particularly among women, according to research in Arthritis Research & Therapy. This can lead to a delayed diagnosis or misdiagnosis of fibromyalgia.

The other important difference is the source of the pain. Spondylitis is an autoimmune disease. Back, hip, and joint pain are caused by inflammation that occurs when the immune system mistakenly attacks healthy tissue.

Fibromyalgia, on the other hand, is believed to occur when the central nervous system becomes hypersensitive to pain signaling. Other sensitivities may also be heightened with fibromyalgia, such as hypersensitivity to temperature or sound.

Making an Accurate Diagnosis

A doctor will determine an axial spondyloarthritis diagnosis based on a physical exam, medical and family history, imaging tests, and blood tests. A doctor will look for the following:

• Back pain that has lasted more than three months, started before age 45, improves with exercise, and does not improve with rest
• MRI that shows active inflammation of the sacroiliac joint
• A positive blood test for the HLA-B27 gene
• Signs and symptoms such as as elevated C-reactive protein (CRP) levels in blood, family history, or uveitis (eye inflammation)

A fibromyalgia diagnosis is determined based on symptoms that have lasted more than three months, including:

• Widespread areas of pain and tender points
• Fatigue despite sleep
• Cognitive problems with thinking and memory

There are no positive blood tests or imaging tests that indicate fibromyalgia. But a doctor may use some tests to eliminate a diagnosis of another inflammatory condition, such as rheumatoid arthritis or lupus.

One MySpondylitisTeam member described their long path to a spondylitis diagnosis: “I had pain for years and doctors tried to diagnose me with fibromyalgia and put me on antidepressants. I was never taken seriously. Then one day while visiting the neurologist several years after all of the blood work was done, the doctor said, ‘Did you know you are HLA-B27 positive?’ I finally found out it wasn’t ‘all in my head,’ nor did I have fibromyalgia.”

Treating Spondylitis vs. Fibromyalgia

Treatments for axSpA are aimed at reducing inflammation and slowing the progress of the disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) are usually the first line of treatment. When disease activity is high and NSAIDs are not effective, disease-modifying antirheumatic drugs (DMARDs) — such as sulfasalazine or biologics including tumor necrosis factor (TNF) inhibitors — may be recommended. Acetaminophen (sold as Tylenol) will not decrease inflammation, but is sometimes used for pain when NSAIDs don’t relieve symptoms.

Corticosteroids are sometimes used to treat flares of spondylitis symptoms. Exercise and physical activity are an important part of most axSpA treatment plans, since spondylitis symptoms worsen with inactivity.

Fibromyalgia treatment aims at pain relief, changing brain chemistry, and lifestyle changes. Treatment options include:

• Antidepressants
• Over-the-counter and prescription pain medicine
• Anti-seizure medications that can reduce neuropathic pain

Fibromyalgia treatment plans also include physical therapy for strength and flexibility, occupational therapy to make work more comfortable, and counseling and cognitive behavioral therapy to help manage stress and cope with the condition.

Spondylitis With Fibromyalgia

It’s not unusual for someone to have both fibromyalgia and spondylitis. In a systematic review of research papers, 115 out of 801 people with axSpA (14 percent) initially also had fibromyalgia, and another 45 (7 percent) went on to develop it. The researchers also suggested that in cases where treatment for axSpA was ineffective, a comorbidity (when two or more conditions occur at the same time) such as fibromyalgia may have gone undiagnosed.

The study also showed that high levels of axSpA disease activity and widespread pain with axSpA were linked to developing fibromyalgia. According to this study, people with axSpA with low levels of widespread pain and disease activity who received effective treatment with biologic TNF inhibitors were more likely to recover from fibromyalgia.

Treating Both Conditions

Treating both conditions together can be a complex process of finding drugs that can reduce the inflammation of axSpA while addressing the pain of fibromyalgia. If you’re having widespread pain with your axSpA and have not been diagnosed with fibromyalgia, it may be helpful to discuss this possibility with your rheumatologist and health care providers. Treating both conditions can help improve outcomes and quality of life.

Effective treatment for both conditions can take time to figure out. One MySpondylitisTeam member expressed their frustration: “I feel my muscles, joints, and spine starting to hurt. I hate having fibromyalgia and ankylosing spondylitis because any little stress causes my whole body to feel like it wants to completely shut down.”

Another member with fibromyalgia described starting their treatment for spondylitis. “I started biologic injections a little over a month ago at my rheumatologist’s office, and I can say they are working very well. For the first time in my life, I don't wake up stiff anymore. I am able to bend without pain,” they wrote. “I suffered severe pain for many years. It took a very long time to figure out what was wrong with me and to get a diagnosis.”

Talk With Others Who Understand

MySpondylitisTeam is the social support network for people with spondylitis and their loved ones. Here, more than 84,000 members come together to ask questions, give advice, and share their stories with others who understand life with spondyloarthritis.

Do you have questions about fibromyalgia and spondylitis? Share your experiences or questions in the comments below, or start a conversation by posting on your Activities page.