If you have chronic back pain that started before age 45, feels worse in the morning, and improves with movement rather than rest, you might have axial spondyloarthritis (axSpA), an inflammatory condition affecting the spine and pelvis that doctors frequently overlook. The average person waits between 6 and 9 years from their first symptoms to receiving a diagnosis, during which untreated inflammation can silently damage joints and increase the risk of heart disease and stroke. Why Is Axial Spondyloarthritis So Hard to Diagnose? AxSpA is frequently mistaken for other causes of back pain, such as osteoarthritis, disc disease, or mechanical injury. This diagnostic confusion happens for several reasons. The pain mimics common conditions that people often attribute to aging or overuse, making it easy to dismiss in its early stages. Standard imaging also misses it. 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. Additionally, 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," explains Abhijeet Danve, MBBS, MD, MHS, director of Yale Medicine's Spondyloarthritis Program. 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. What Symptoms Should Prompt You to Get Screened? 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. 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, 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. How to Use the New A-Tool Screening for Early Detection A new, free online screening tool called the A-Tool can help you determine if you should see a rheumatologist. The modified version includes only 8 yes or no questions about back pain, other symptoms, and family history. The screening provides your probability of having axSpA, and a probability greater than 33% suggests you should see a rheumatologist for further evaluation. - Gradual Onset: Symptoms that develop slowly over time, not from a sudden injury or trauma - Movement Response: Pain that improves with exercise but does not improve with rest, distinguishing it from mechanical back pain - Night Pain Pattern: Pain that worsens in the second half of the night, a hallmark of inflammatory conditions - Morning Stiffness: Stiffness lasting more than 30 minutes after waking, indicating inflammatory activity - Early Age of Onset: Back pain beginning at any point before age 45, when axSpA typically emerges 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". What Happens During a Rheumatologist Evaluation? 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 important 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 explains. "But imaging of the pelvis can show inflammation in the sacroiliac joints and is more likely to help confirm axSpA". What Treatment Options Are Available Once Diagnosed? The good news is that effective treatments exist for axSpA. Treatment options 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 are 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 are 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". 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 helps prevent serious complications, such as spinal fusion, and reduces the inflammation that contributes to high blood pressure, heart disease, stroke, and blood clots. If your A-Tool probability is greater than 33% or you have chronic back pain lasting more than three months with the characteristics described above, consider seeing a rheumatologist for evaluation.
