• Back pain is usually caused by injuries or mechanical problems, but it may be due to inflammatory diseases in which the spine becomes progressively damaged.
• Inflammatory back pain tends to follow certain patterns that set it apart from mechanical back pain.
• Recognizing the features of inflammatory back pain can help you better track your symptoms and give your doctor insight into possible causes of your pain.

Around 4 out of 5 people experience back pain over the course of their life. Most of the time, back pain is caused by mechanical issues, such as injuries or conditions that disrupt the way muscles, bones, and connective tissue fit or work together. However, for as many as 20 percent of people, back pain is caused by inflammatory disease in which a dysfunctional immune system attacks the body’s tissues.

One such condition is axial spondyloarthritis (axSpA), a type of inflammatory arthritis. This condition causes inflammation in the spine and hips, leading to pain and swelling in the lower back. In the U.S. alone, axSpA is the cause of back pain for about 5.5 million people. Both types of axSpA — ankylosing spondylitis and nonradiographic axial spondyloarthritis — can cause back, hip, and buttock pain.

It can be difficult to determine when you might have inflammatory arthritis rather than mechanical back pain, but the type you have makes a big difference in how your condition is treated and what your long-term outcomes may be.

If you notice any of these key signs of inflammatory back pain, it may be a good idea to talk to your doctor about whether you might have axSpA.

1. Your Back Pain Gets Better With Exercise

Most people who have back pain will want to lay down, sit, or stop moving in order to get some relief. This is a typical feature of mechanical back pain. However, inflammatory back pain tends to get better when you’re more active.

If you find that exercise helps relieve your back pain or notice that your pain gets worse when you’ve been sitting all day, there is a better chance that you have an inflammatory condition.

2. You Experience Morning Stiffness and Pain

Conditions that cause back pain can sometimes also lead to stiffness, especially in the morning. For mechanical pain, this stiffness is often mild and tends to go away quickly once you start moving around. However, axSpA leads to moderate back stiffness that lingers for 30 minutes or more in the mornings.

Inflammatory back pain or stiffness may begin very early in the morning before it’s time to get up. Waking up in the second half of the night because of discomfort in your back is also a telling symptom of an inflammatory condition.

3. Your Pain Began Slowly and Has Lasted a Long Time

How your symptoms first appear and how they progress can be a clue as to whether your back pain is mechanical or inflammatory.

Mechanical back pain may come on suddenly, or it may start more slowly. On the other hand, when back pain is caused by inflammatory factors, it usually has what doctors call “insidious onset” — it begins very gradually. You may experience small twinges of discomfort that grow into bigger pains. If you suddenly woke up one day with a lot of back pain, it’s unlikely that you have a condition like axSpA.

Back pain can also look different over time when it has mechanical versus inflammatory causes. In general, pain can be acute (lasting a few days or a few weeks) or chronic (continuing for 12 weeks or longer). Mechanical back pain may be either, but is more likely to be acute — it often quickly gets better on its own with some self-care. However, inflammatory conditions may lead to chronic back pain that continues for at least three months and gradually worsens over time.

4. You Developed Back Pain at a Young Age

How old you were when your back pain began may also provide some insight. Mechanical problems can appear at any age — both older or younger adults can throw their back out, exercise too hard, or sleep in a pain-inducing position. However, inflammatory back pain usually appears when a person is under 40 years of age.

If your back starts aching later in life, it may be due to another condition such as spondylosis (general wear and tear of the spinal discs caused by age).

5. You Have Other Key Symptoms

Axial spondyloarthritis doesn’t affect just the back — it tends to affect the sacroiliac joints in the pelvis as well. People with axSpA often experience pain in the buttocks that regularly switches from one side to the other.

Mechanical back pain typically just involves the back. However, axSpA can affect other tissues throughout the body, which may lead to widespread symptoms. In particular, up to half of people with spondylitis will have redness and pain in one eye at some point in their life. This inflammatory condition, called uveitis, can also lead to blurry vision and pain or discomfort when looking at bright lights.

Other symptoms that may appear with axSpA include:

• Swelling, pain, or stiffness in at least four joints throughout the body, especially in the feet and lower legs
• Enthesitis (inflammation where the tendons or ligaments connect to bone), which may lead to sharp pains in the heels, chest, or other areas
• Dactylitis or “sausage digits” — swelling in fingers or toes
• Other inflammatory conditions such as psoriasis or inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis

If you experience these symptoms in addition to chronic lower back pain, it may be more likely that your back pain is caused by an inflammatory condition such as axial spondyloarthritis.

Talking to Your Doctor About axSpA

If you think your back pain might be caused by inflammation, talk to your doctor. It may help to keep a symptom diary to show to your health care provider.

Note down where in your body you experience pain and what the pain feels like. You can also record when the pain appears: Does it get better or worse at certain times of the day? Does your pain change after you’ve been more active? Additionally, make a note of any other potential symptoms or health changes you experience.

Next Steps

If your doctor suspects you have inflammatory back pain, they may refer you to a rheumatologist. They may recommend tests to help diagnose axial spondylitis or rule out other types of inflammatory arthritis that could cause back pain, such as psoriatic arthritis (PsA), rheumatoid arthritis, enteropathic arthropathy, or reactive arthritis. Your doctor will likely perform a physical examination, recommend blood tests to look for signs of inflammation, and suggest imaging tests such as X-rays to detect signs of bone damage.

How you treat your back pain will depend on what is causing it. Acute back pain caused by mechanical factors often gets better using treatments like heat, ice, rest, stretching, or nonsteroidal anti-inflammatory drugs (NSAIDs).

Most of these treatments won’t help ease pain from axSpA, because they don’t address the underlying inflammation. The exception is NSAIDs, which are often used to manage inflammatory back pain. If NSAIDs aren’t effective at controlling pain, disease-modifying antirheumatic drugs (DMARDs) such as biologics may be used. DMARDs of different classes target and modify different aspects of the immune system to reduce inflammation. These classes of DMARDs include:

• Tumor necrosis factor (or TNF) inhibitors
• Janus kinase (JAK) inhibitors
• IL-17A inhibitors

Getting regular exercise and having a physical therapy regimen are also important for people with axSpA. Moving your body helps prevent your spine from getting too stiff.

Proper treatment for axSpA can slow down the disease progress, prevent further damage, and improve your quality of life.

Talk With Others Who Understand

On MySpondylitisTeam, the social network for people with spondylitis and their loved ones, more than 83,000 members come together to ask questions, give advice, and share their stories with others who understand life with spondylitis.

Does your back pain have inflammatory features? Have you talked with your doctor about these details? Share your experience in the comments below, or start a conversation by posting on MySpondylitisTeam.