Spondylitis, also called spondyloarthritis, is an autoimmune and autoinflammatory disease that mainly affects the spine and sacroiliac joints. It can also affect peripheral joints (such as knees, ankles) or cause symptoms in other areas of the body, such as the eyes, skin, and digestive system. These conditions are called comorbidities or complications, and they can affect how spondylitis is treated and how it feels day to day.

Understanding the conditions linked to spondylitis can help you and your healthcare team manage symptoms effectively and avoid long-term problems.

What Diseases Are Associated With Spondylitis?

Below is a list of conditions that have been associated with spondylitis. Keep in mind that just because a condition is associated with spondylitis doesn’t mean you’ll automatically develop it. Remember, everyone’s body and spondylitis journey is different.

1. Inflammatory Bowel Disease

In addition to inflammation and pain in the joints, some types of spondylitis can cause inflammation in the digestive tract known as inflammatory bowel disease (IBD). Crohn’s disease and ulcerative colitis are the most common types of IBD, and symptoms may include abdominal pain, diarrhea, and weight loss. Nearly 50 percent of people with a type of spondylitis called ankylosing spondylitis (AS) develop a form of IBD.

2. Psoriasis and Psoriatic Arthritis

Psoriasis is a common autoimmune disease that can cause raised, scaly patches on the skin due to systemic (bodywide) inflammation. One study noted that approximately 10 percent of people with ankylosing spondylitis have psoriasis. When psoriasis occurs with joint pain, it’s referred to as psoriatic arthritis (PsA). PsA is part of the spondylitis family and often affects the fingers, toes, and spine.

3. Eye Inflammation

Spondylitis and other autoimmune diseases, such as rheumatoid arthritis, can cause eye inflammation. Spondylitis is mainly associated with the following eye concerns:

• Uveitis — Inflammation in the uvea (vascular layer of the eye), which is between the sclera (white part of the eye) and retina (layer of tissue in the back of the eye). This is the most frequent eye involvement associated with spondylitis.
• Iritis — Swelling and redness in the iris (the color part of the eye), which can become painful and cause light sensitivity.
• Glaucoma — Damage to the optic nerve due to high pressure and inflammation in the eye.
• Cataracts — Inflammation that causes the lenses in the eyeball to become cloudy.

According to the Spondylitis Association of America, up to 50 percent of those with spondylitis will experience some type of eye inflammation at least once. These conditions may lead to vision loss if untreated.

4. Enthesitis

Enthesitis is inflammation in the entheses, the place where tendons and ligaments connect to bone. It’s common in people with forms of spondylitis, and it can cause pain and discomfort in the shoulders, hips, knees, elbows and most frequently in the heels. It may eventually lead to the formation of new bone, known as a bone spur. It can also lead to plantar fasciitis — inflammation in the band of tissue in the sole of the foot, which can cause heel or arch pain.

5. Osteoporosis

Osteoporosis is a condition that causes bones to become weak and break easily, often because of a decrease in bone mineral density. People with spondylitis are at higher risk of developing osteoporosis, and it can also be a side effect of long-term treatment with corticosteroids. One study found that individuals with ankylosing spondylitis were more likely to develop osteoporosis earlier than the general population.

6. Costochondritis

Spondylitis can also be connected to costochondritis, inflammation of the cartilage where the ribs meet the breastbone. This can cause temporary, but intense, chest pain that can be mistaken for a heart attack.

7. Curvature of the Spine

Common complications of ankylosing spondylitis include fusion of the vertebrae in the spine, meaning the bones of the spine join together. This fusion causes the spine to stiffen and reduces movement. If fusion of the spine starts to curve forward, it’s referred to as kyphosis. These fusions may also lead to more frequent fractures.

8. Lung Complications

Advanced ankylosing spondylitis can cause curvature of the spine and fusions of vertebrae that affect breathing and lung function. This dramatically limits movement of the chest wall and can result in lung disease such as pulmonary fibrosis and an increased risk of lung infections.

9. Heart Conditions

Spondylitis can increase the risk of several types of heart disease due to inflammation and long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen. Up to 10 percent of people with ankylosing spondylitis also have a heart condition, according to the Spondylitis Association of America.

Some associated heart conditions include:

• Ischemic heart disease — Reduced amounts of blood in the heart muscle, which increases the risk of trouble breathing, chest pain, and heart attacks. This is usually caused by coronary artery disease.
• Aortitis — Inflammation of the aorta, the large artery responsible for carrying blood out of the heart and into the rest of the body. Aortitis can cause hypertension (high blood pressure) and aortic insufficiency where the aorta can’t circulate enough blood to the body.
• Arrhythmias (abnormal heart rhythms) — Occur when the heart beats too slowly (bradycardia) and too quickly (tachycardia) because of electrical issues. With arrhythmias, the heart doesn’t pump blood as efficiently, and it may cause skips in your heartbeat.
• Cardiomyopathy — The weakening of the heart muscle due to inflammation. This can make it hard to pump blood into the body and lead to further complications like blood clots, heart failure, and cardiac arrest.

10. Cauda Equina Syndrome

Cauda equina syndrome (CES) is a rare but serious nerve condition that affects the lower spine. If nerves in the lower spine become compressed as a result of ankylosing spondylitis, it can cause numbness and weakness in the lower body and problems with bladder or bowel control. Sudden CES may require emergency surgery to prevent damage.

When To Talk to Your Doctor About New Symptoms

If you notice new or worsening symptoms alongside your current symptoms of spondylitis, it’s important to speak with a healthcare professional. These symptoms may include:

• Chest pain
• Trouble breathing
• Severe joint or lower back pain
• Eye pain or changes in vision, such as blurred vision or light sensitivity
• Skin rashes or flares
• Lasting digestive issues like diarrhea and abdominal pain

If you’re experiencing any of these symptoms, your healthcare provider may make changes to your current treatment plan. Early intervention can help provide pain relief, prevent serious complications, and improve your quality of life.

Living with spondylitis can be challenging, especially if other conditions are involved. By understanding the possible complications and staying alert to any new symptoms, you can take steps to protect your health and maintain your well-being.

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