Ankylosing spondylitis is an inflammatory disease that, over time, can cause some of the bones in the spine (vertebrae) to fuse. This fusing makes the spine less flexible and can result in a hunched posture. If ribs are affected, it can be difficult to breathe deeply.
Ankylosing spondylitis affects men more often than women. Signs and symptoms typically begin in early adulthood. Inflammation can also occur in other parts of the body — most commonly, the eyes.
There is no cure for ankylosing spondylitis, but treatments can lessen symptoms and possibly slow progression of the disease.
Early signs and symptoms of ankylosing spondylitis might include pain and stiffness in the lower back and hips, especially in the morning and after periods of inactivity. Neck pain and fatigue also are common. Over time, symptoms might worsen, improve or stop at irregular intervals.
The areas most commonly affected are:
- The joint between the base of the spine and the pelvis
- The vertebrae in the lower back
- The places where tendons and ligaments attach to bones, mainly in the spine, but sometimes along the back of the heel
- The cartilage between the breastbone and the ribs
- The hip and shoulder joints
Ankylosing spondylitis has no known specific cause, though genetic factors seem to be involved. In particular, people who have a gene called HLA-B27 are at a greatly increased risk of developing ankylosing spondylitis. However, only some people with the gene develop the condition.
Men are more likely to develop ankylosing spondylitis than are women. Onset generally occurs in late adolescence or early adulthood. Most people who have ankylosing spondylitis have the HLA-B27 gene. But many people who have this gene never develop ankylosing spondylitis.
In severe ankylosing spondylitis, new bone forms as part of the body’s attempt to heal. This new bone gradually bridges the gap between vertebrae and eventually fuses sections of vertebrae. Those parts of the spine become stiff and inflexible. Fusion can also stiffen the rib cage, restricting lung capacity and function.
Other complications might include:
- Eye inflammation (uveitis). One of the most common complications of ankylosing spondylitis, uveitis can cause rapid-onset eye pain, sensitivity to light and blurred vision. See your doctor right away if you develop these symptoms.
- Compression fractures. Some people’s bones weaken during the early stages of ankylosing spondylitis. Weakened vertebrae can crumple, increasing the severity of a stooped posture. Vertebral fractures can put pressure on and possibly injure the spinal cord and the nerves that pass through the spine.
- Heart problems. Ankylosing spondylitis can cause problems with the aorta, the largest artery in the body. The inflamed aorta can enlarge to the point that it distorts the shape of the aortic valve in the heart, which impairs its function. The inflammation associated with ankylosing spondylitis increases the risk of heart disease in general.
During the physical exam, your health care provider might ask you to bend in different directions to test the range of motion in your spine. Your provider might try to reproduce your pain by pressing on specific portions of your pelvis or by moving your legs into a particular position. You also may be asked to take a deep breath to see if you have difficulty expanding your chest.
X-rays allow doctors to check for changes in joints and bones, though the visible signs of ankylosing spondylitis might not be evident early in the disease.
An MRI uses radio waves and a strong magnetic field to provide more-detailed images of bones and soft tissues. MRI scans can reveal evidence of ankylosing spondylitis earlier in the disease process, but are much more expensive.
There are no specific lab tests to identify ankylosing spondylitis. Certain blood tests can check for markers of inflammation, but inflammation can be caused by many different health problems.
Blood can be tested for the HLA-B27 gene. But many people who have that gene don’t have ankylosing spondylitis and people can have the disease without having the gene.
The goal of treatment is to relieve pain and stiffness and prevent or delay complications and spinal deformity. Ankylosing spondylitis treatment is most successful before the disease causes irreversible damage.
Nonsteroidal anti-inflammatory drugs (NSAIDs) — such as naproxen (Aleve, Naprosyn, others) and ibuprofen (Advil, Motrin IB, others) — are the medications doctors most commonly use to treat ankylosing spondylitis. These medications can relieve inflammation, pain and stiffness, but they also might cause gastrointestinal bleeding.
If NSAIDs aren’t helpful, your doctor might suggest starting a tumor necrosis factor (TNF) blocker or an interleukin-17 (IL-17) inhibitor. These drugs are injected under the skin or through an intravenous line. These types of medications can reactivate untreated tuberculosis and make you more prone to infections.
Examples of TNF blockers include:
- Adalimumab (Humira)
- Certolizumab pegol (Cimzia)
- Etanercept (Enbrel)
- Golimumab (Simponi)
- Infliximab (Remicade)
IL-17 inhibitors used to treat ankylosing spondylitis include secukinumab (Cosentyx) and ixekizumab (Taltz).
Physical therapy is an important part of treatment and can provide a number of benefits, from pain relief to improved strength and flexibility. A physical therapist can design specific exercises for your needs. To help preserve good posture, you may be taught:
- Range-of-motion and stretching exercises
- Strengthening exercises for abdominal and back muscles
- Proper sleeping and walking positions
Most people with ankylosing spondylitis don’t need surgery. Surgery may be recommended if you have severe pain or if a hip joint is so damaged that it needs to be replaced.
Lifestyle and home remedies
Lifestyle choices can also help manage ankylosing spondylitis.
- Stay active. Exercise can help ease pain, maintain flexibility and improve your posture.
- Don’t smoke. If you smoke, quit. Smoking is generally bad for your health, but it creates additional problems for people with ankylosing spondylitis, including further hampering breathing.
- Practice good posture. Practicing standing straight in front of a mirror can help you avoid some of the problems associated with ankylosing spondylitis.