Could Your Back Pain Be From Axial Spondyloarthritis?

If you have chronic back pain that started before age 45, feels worse in the morning, and improves with movement—not rest—you may have axial spondyloarthritis (axSpA), an inflammatory condition affecting the spine and pelvis. A new, free online screening tool called the A-Tool can help you determine if you should see a rheumatologist.

AxSpA is frequently mistaken for other causes of back pain, such as osteoarthritis, disc disease, or mechanical injury. The average person waits 6 to 9 years between first symptoms and diagnosis. During that time, untreated inflammation can affect quality of life and lead to complications even though effective treatments exist.

“This long delay in diagnosis of a treatable condition is unacceptable,” says Abhijeet Danve, MBBS, MD, MHS, director of Yale Medicine’s Spondyloarthritis Program and creator of the A-Tool. “When someone has this condition, we have definitive treatments that work.”

Axial spondyloarthritis is an inflammatory condition in which the body’s immune system attacks the spine and sacroiliac joints—the joints that connect the spine to the pelvis. It is part of a larger group of conditions called spondyloarthritis.

AxSpA typically begins in a person’s 20s, 30s, or 40s, though symptoms can start as early as late adolescence. Pain and stiffness develop gradually and may be mild, which makes the condition easy to overlook in its early stages.

If untreated, axSpA can lead to chronic pain in the spine, lower back, and buttocks that may spread to the heels, shoulders, and neck. It can also cause inflammation in the eyes (uveitis or iritis), which requires immediate medical attention.

The disease is also linked to other conditions, including ulcerative colitis, Crohn’s disease, and psoriasis. Many people experience significant fatigue, and ongoing inflammation can increase the risk of heart disease and stroke. In advanced cases, untreated axSpA may cause the bones of the spine to fuse.

Several factors make axSpA difficult to identify. The pain mimics other conditions—back pain and stiffness are common symptoms that many people attribute to aging, overuse, or osteoarthritis.

Standard imaging can miss it, too. AxSpA starts in the sacroiliac joints, which are difficult to see clearly on a standard X-ray. An MRI of the lumbar spine alone may not include the pelvis, where inflammation first appears. “That’s how the diagnosis is sometimes missed,” Dr. Danve says.

Finally, the condition is not immediately disabling. “Pain responds well to nonsteroidal anti-inflammatory drugs (NSAIDs), so people may continue taking NSAIDs without seeking medical attention,” Dr. Danve says. Many people continue working and functioning, so they delay seeing a doctor or don't mention the pain during routine visits if it doesn’t happen to be bothering them at that time.

The original A-Tool is a free, 12-question online survey that helps identify people who may have axSpA. Dr. Danve further modified the tool to include only 8 yes or no questions about back pain, other symptoms, and family history.

The modified A-Tool scoring provides your probability of having axSpA. A probability greater than 33% suggests you should see a rheumatologist for further evaluation. The screening is for informational purposes only and is not a diagnosis.

A 2025 study published in Rheumatology Advances in Practice tested the original A-Tool with 1,200 people who had back pain. Based on their results, 100 were evaluated by a rheumatologist, and one in three was diagnosed with axSpA. “The tool increases probable detection of axSpA from a baseline of 5% to as high as 33%,” Dr. Danve says. “That’s a huge improvement.”

Consider taking the A-Tool if you have ongoing back pain for more than three months, beginning at any point before 45, especially if you have the following:

• Gradual onset of symptoms (not a sudden injury)
• Pain that improves with exercise
• Pain that does not improve with rest
• Night pain, especially in the second half of the night
• Morning stiffness lasting more than 30 minutes

Even if your symptoms are mild, screening may help you avoid years of delayed diagnosis.

A rheumatologist will evaluate you through a combination of detailed questioning, physical examination, blood tests, imaging, and family history review. The physical examination will assess your range of motion, pain patterns, and joint tenderness.

Two blood tests can provide clues. One measures C-reactive protein (CRP), a marker of inflammation that is elevated in about half of people with axSpA. The other tests for the HLA-B27 gene. Up to 90% of people with axSpA carry this gene, though only a small percentage of people with the gene develop the condition.

An MRI of the pelvis can reveal inflammation in the sacroiliac joints even at early stages, which is a key sign of axSpA. Standard lumbar spine imaging may miss this area. “When a patient complains of back pain, a doctor may order an MRI of the lumbar spine that does not include imaging of the sacroiliac joints,” Dr. Danve says. “But imaging of the pelvis can show inflammation in the sacroiliac joints and is more likely to help confirm axSpA.”

Your rheumatologist will also ask about your family and medical history. AxSpA can cluster in families. “One family member has psoriasis, another has Crohn’s disease, or the patient themselves may have had a condition such as psoriasis, inflammatory bowel disease, or eye inflammation,” Dr. Danve says.

Your doctor will discuss treatment options, which may include:

• NSAIDs, to block enzymes involved in inflammation. About 15% to 20% of people manage well with NSAIDs alone. However, long-term use can cause side effects, and not everyone tolerates them.

• Biologic medications, given by injection or infusion to block immune system signals that cause inflammation. They are often used when NSAIDs are not enough. Two classes of biologic drugs are FDA-approved for axSpA: TNF blockers, of which five medications are available, and interleukin-17 blockers, of which three medications are available. Many people improve with biologics, though not everyone responds.
• Janus kinase (JAK) inhibitors, oral small-molecule medications taken once or twice daily. They limit the action of enzymes involved in inflammation. Two are FDA-approved for axSpA and may help people for whom NSAIDs and biologics have not worked.

“These medications don’t fully ease symptoms, but they can allow patients to live a better life,” Dr. Danve says. “Other problems like intestinal inflammation, uveitis, and psoriasis get better, and their sleep and work productivity also may improve.”

Many people live with mild to moderate back pain for years without mentioning it to their doctor. They may try physical therapy, buy a new mattress, or assume the discomfort is due to normal aging. “It’s not completely incapacitating—people don't become wheelchair-bound—so many learn to live with it,” Dr. Danve says.

But untreated axSpA can quietly affect your sleep, work, and daily activities. It may also lead to unnecessary procedures or surgeries if the underlying cause is not identified. Treatment also helps prevent serious complications, such as spinal fusion, and reduces the inflammation that contributes to high blood pressure, heart disease, stroke, and blood clots.

See a rheumatologist if your A-Tool probability is greater than 33%, if you have chronic back pain that started before age 45 and improves with exercise but not rest, if you have morning stiffness lasting more than 30 minutes, or if you have a family history of psoriasis, inflammatory bowel disease, or axSpA.

Seek immediate care if you develop sudden eye pain, redness in your eyes, or vision changes, which may signal a medical emergency.

You do not need to worry if your back pain started after an injury or strain, if it improves with rest, or if it starts later than age 45 and there are no other symptoms of axSpA.

Early diagnosis and treatment can help you avoid complications and improve your symptoms and quality of life. The A-Tool offers a solution for a problem that has lacked a practical screening tool, Dr. Danve says. “The tool is simple and practical, and best of all, can be completed by patients themselves.”