AS Affects More Than Your Back

Medically Reviewed by Michael W. Smith, MD on October 06, 2021
4 min read

Carrie Bonin was just 17 when her knees began to hurt so badly that she could barely walk. The pain tended to come and go, but was worst in the mornings. Bonin told her doctor about her agony.

"His response was, ‘Most people wake up with some pain in the morning. It’s completely normal,’" recalls Bonin, now 46, of Monroe, CT.

Over the next several years, Bonin endured the same pain in her hips, thumbs, wrists, and feet. Her doctor thought it might be related to Bonin’s earlier car accident. They prescribed anti-inflammatory pills, cortisone shots, and physical therapy. This gave her little relief.

“I was 21, but I waddled with the stiffness of a 90-year old woman,” Bonin says. It wasn’t until she was 25 that an orthopedic surgeon finally identified her ailment: ankylosing spondylitis (AS).

Lower back pain is a hallmark symptom of AS. But it’s not the only one. AS often can affect the joints in places like the shoulder or hips. That’s especially true in younger people, says Lawrence Brent, MD, a professor of medicine in the section of rheumatology at Temple University Hospital in Philadelphia.

AS can also cause enthesitis, or inflammation where your ligaments or tendons attach to your bones. The two most common spots are the Achilles tendon in your heel and plantar fascia in your foot. That’s where Bonin hurt the most. Today, she wears special inserts in her shoes and applies anti-steroid cream to her feet every day.

Unfortunately, some people with AS can go years before they get the right diagnosis. Some may not think to report their pain to their doctors. Other times, it’s because “some of the tendon-related issues are easy to overlook, especially if you’re being seen by your primary care doctor who may not be thinking about inflammatory arthritis,” says Erin Bauer, MD, a rheumatologist at Virginia Mason Medical Center in Seattle.

AS is a lifelong condition that in severe cases can lead to permanent damage to your posture and mobility and other problems. Pain that appears in places other than your back could be a sign that you have a more serious form of the disease.

Hips and shoulders. Pain in these locations affects about 1 in 3 people with AS. It usually comes on little by little. The pain can spread to your groin, knees, or the front of your thighs.

Eyes. About 40% of people with AS have an eye inflammation called uveitis. If you notice pain or redness, see your doctor right away. They may prescribe treatments like steroid eye drops. 

Gut. As many as 1 in 10 people with AS get an inflammatory bowel disease (IBD) such as Crohn’s disease or ulcerative colitis. Symptoms of IBD include bloody diarrhea, weight loss, or tiredness.

Even if you don’t have IBD, you may have tummy trouble from the nonsteroidal anti-inflammatory drugs (NSAIDs) that are often used to treat AS, says Bauer of Virginia Mason. If you have symptoms like nausea, vomiting, heartburn, or diarrhea, let your doctor know. You may need to switch your medicines or cut back on them.

Jaw. About 10% of people with AS have jaw inflammation that makes it very hard for them to eat. If your jaw hurts, see your dentist, who can prescribe pain relievers like muscle relaxants or even a mouth guard.

Bones. Osteoporosis, or low bone density, affects about half the people with AS.  Two ways to help ward off this disease is with supplements and exercise. You need 1,000-1,200 milligrams of calcium and 400-1,000 IU of vitamin D a day. Weight-bearing exercises like walking help keep your bones strong. Also, tai chi, yoga, and other exercises that improve your balance may prevent falls.

Lungs. Sometimes AS can make it hard to breathe because the stiffness between the ribs and spine prevent your chest from expanding, says Stuart Kaplan, MD, chief of rheumatology at Mount Sinai South Nassau in Oceanside, NY. You may also get chest pain from scar tissue around your rib joints. If you notice either, see your doctor right away. Ice packs and deep-breathing exercises can also help.

Heart. AS makes you more likely to get heart disease. Your aorta, the artery that pumps blood from your heart to the rest of your body, can become swollen. Your heart can beat too quickly or too slowly.

AS-linked inflammation itself may also raise your chances of heart disease, Kaplan says. Keeping your weight, blood pressure, and cholesterol under control can help lower those risks. You should also get an echocardiogram, or heart ultrasound, annually.