What is ankylosing spondylitis?
Ankylosing spondylitis (say "ang-kill-LOH-sing spawn-duh-LY-tus") is a long-term form of arthritis that most often occurs in the spine. It can cause pain and stiffness in the low back, middle back, buttocks, and neck, and sometimes in other areas such as the hips, chest wall, or heels. It can also cause swelling and limited motion in these areas. This disease is more common in men than in women.
There is no cure, but treatment can control symptoms and prevent the disease from getting worse in most cases. Most people are able to do their normal daily activities and can still work.
This disease can cause several other problems. You may have redness and pain in the colored part of your eye (iritis). You also may have trouble breathing as your upper body begins to curve and your chest wall begins to stiffen.
What causes ankylosing spondylitis?
The cause is unknown, but it may run in families. Most people with ankylosing spondylitis are born with a certain gene, HLA-B27. But having this gene does not mean that you will get the disease.
Research suggests that bacterial infections and your environment may have roles in causing this disease.
What are the symptoms?
This disease causes mild to severe pain in the low back and buttocks that is often worse in early morning. Some people have more pain in other areas, such as the hips or heels. The pain usually gets better slowly as you move around and are active. Ankylosing spondylitis most often begins anywhere from the teenage years through the 30s.
It gets worse slowly over time as swelling of the ligaments, tendons, and joints of the spine causes the bones of the spine to join, or fuse, together. This leads to less range of movement in the neck and low back.
As the spine fuses and stiffens, the neck and low back lose their normal curve. The middle back curves outward. This can keep you in a bent-forward position and may make it hard for you to walk.
As the small joints that connect the ribs and collarbone to the breastbone get inflamed, you may find that it's harder for you to breathe. Other parts of the body, such as your eyes and your other joints, may also swell. Sometimes the disease affects the lungs, the heart valves, the digestive tract, and the major blood vessel called the aorta.
How is ankylosing spondylitis diagnosed?
The early signs of this disease—dull pain in the low back and buttocks—are common. Your doctor will ask about your symptoms and if they have become worse over time. Your doctor will also ask if you have a family history of this joint disease or others like it.
The clearest sign of the disease is a change in the sacroiliac joints at the base of the low back. This change can take up to a few years to show up on an X-ray.
How is it treated?
Treatment includes exercise and physical therapy. These will help reduce stiffness so that you can stand up straighter and move around better. Your doctor will also give you medicine for pain and swelling.
Because people with ankylosing spondylitis may be at a higher risk for spinal cord injury, it's important that you wear a seat belt every time you drive or ride in a car.
You will need to get regular eye exams to check for inflammation in your eye, called iritis. You may use a device such as a cane to help you walk and to help reduce stress on your joints.
Surgery for the spine is rarely needed. You may want to think about hip or knee replacements if you have severe arthritis in those joints.
There is no cure for this disease. But early diagnosis and treatment can help relieve pain and stiffness and allow you to keep doing your daily activities for as long as possible.
Ankylosing spondylitis is inflammation primarily of the joints of the spine. But it can also involve inflammation of the eye, other joints—especially those in the hips, chest wall, and around the heels—and, on occasion, the shoulders, wrists, hands, knees, ankles, and feet. Although it is unusual, ankylosing spondylitis can also cause changes such as thickening of the major artery (aorta) and the valve in the heart called the aortic valve.
If the inflammation continues over time, it will lead to scarring and permanent damage. In some people the disease is mild and progresses slowly, and symptoms may never become severe. Other people may have a more aggressive disease process.
Whether ankylosing spondylitis gets worse depends on a number of things such as how old you were when the disease began, how early it was diagnosed, and what joints are involved. It's too early to tell yet, but experts hope that early treatment with newer medicines will slow or minimize the inflammation, prevent scarring, and limit the progression of the disease.
Mild or early ankylosing spondylitis
Ankylosing spondylitis usually starts with dull pain in the low back and back stiffness. Some people with ankylosing spondylitis have "flares" of increased pain and stiffness that may last for several weeks before decreasing again.
- Affected bones of the low back, middle back, hips, or neck may become painful, stiff, and limited in motion. Pain tends to increase slowly over a period of weeks or months, and it is often hard to point to exactly where the pain is. Stiffness is usually worse in the morning and usually lasts for more than one hour. Pain is often noticeable in the early morning hours of sleep, such as between 3 a.m. and 6 a.m. Physical activity often helps decrease pain and stiffness.
- Some people feel tired as the disease progresses. This tiredness comes from the body fighting the inflammatory process that is part of ankylosing spondylitis and also from ongoing stiffness and pain.
- The colored part of the eye (iris) may become inflamed. Symptoms of iritis include redness and pain in the eye and sensitivity to light.
Severe or advanced ankylosing spondylitis
If, over time, the inflammation continues, it will lead to scarring and permanent damage.
- Scarring in the spine causes the joints of the spine to grow together (fuse, or "ankylose").
- As the bones fuse, back pain will gradually go away, but the spine will remain very stiff and unable to bend. The fused spine is more likely to break (fracture) if injured, especially the neck (cervical spine).
- Changes in the spine can cause problems with balance, safety, and mobility. The upper spine can curve forward until eventually the person has a hard time looking straight ahead. Also, as the spine loses its natural curves, it becomes hard to balance while standing and walking, especially if the hips are also affected.
- Breathing can become difficult as the upper body curves forward and the chest wall stiffens. Severe ankylosing spondylitis can also cause scarring of the lungs (pulmonary fibrosis) and an increased risk of lung infection. This can cause even greater problems in smokers, because their lungs are already more prone to lung infection and scarring.
- Scarring in the eye from uncontrolled iritis can lead to permanent visual impairment and glaucoma.
- In rare cases, the heart muscle can become scarred and the heart valves may become inflamed. The heart may be unable to pump properly (heart failure). The main artery leading from the heart (aorta) can also be affected by becoming inflamed and enlarged near where it leaves the heart.
- Bowel inflammation is sometimes linked with ankylosing spondylitis.
- The kidneys can be affected by taking medicines over a long period of time.
- Some people who have ankylosing spondylitis for many years develop cauda equina syndrome from scarring around the nerves at the end of the spinal cord. This condition can cause loss of feeling in the saddle area of the groin and legs. It can also cause problems with bowel and bladder control and sexual activity. Talk to your doctor if you start having problems controlling your bowels or bladder.
The stiffening of the chest can feel like the discomfort or "heaviness" of a heart attack. Ankylosing spondylitis can also cause the heart to work less efficiently.
If you have any symptoms of heart or lung problems—including heaviness of the chest or pain with deep breathing—talk to a doctor right away to make sure you don't have any serious heart or lung problems. For more information on heart and lung problems, see the topics Heart Attack and Unstable Angina and Pleurisy.
Ankylosing spondylitis is one disease in a group of joint diseases called the spondyloarthropathies (say "spon-dill-o-ar-THROP-a-thees"). These include psoriatic arthritis, reactive arthritis, and enteropathic arthritis (joint problems linked with inflammatory bowel disease). Although inflammation of the spine also occurs in these other conditions, it is less common and less severe than the inflammation that occurs in ankylosing spondylitis.
Exams and Tests
Your doctor will use a medical history, physical exam, and X-ray to diagnose ankylosing spondylitis.
By asking questions about your medical history, your doctor can evaluate your symptoms. Most people with ankylosing spondylitis have back pain with four or five of the following characteristics:
- Begins before the age of about 35
- Starts and gets worse gradually
- Persists for at least 3 months
- Is linked with morning stiffness that usually lasts for more than one hour
- Improves with exercise
Your doctor will want to know whether you have any family members who have ankylosing spondylitis or a related joint disease. Many people with ankylosing spondylitis have a family member with the same condition. He or she may also ask whether you have had ongoing diarrhea, abdominal (belly) pain, multiple infections of the cervix (in women) or urethra (more common in men), psoriasis, or inflammation of the eye chamber (uveitis). These could be clues to having a condition other than ankylosing spondylitis.
You will have a physical exam to see how stiff your back is and whether you can expand your chest normally. Your doctor will also look for tender areas, especially over the points of the spine, the pelvis, the areas where your ribs join your breastbone, and your heels. You may experience chest pain and stiffness with ankylosing spondylitis.
Tests related to ankylosing spondylitis include:
- X-rays of the spine and pelvis to check for bone changes (bony erosions, fusion, or calcification of the spine and sacroiliac joints). Certain changes in the sacroiliac joint confirm the diagnosis of ankylosing spondylitis. But those changes can take several years to develop enough to show on X-ray. MRI and CT scan are more sensitive than X-ray. If no changes to the sacroiliac joints show on the X-ray but your doctor still suspects ankylosing spondylitis, an MRI or CT scan may allow an earlier diagnosis. Ultrasound is being studied as a way to diagnose ankylosing spondylitis earlier.
- Blood tests. These may include:
- C-reactive protein (CRP) or sedimentation rate (sed rate) to look for inflammation.
- Rheumatoid factor or antinuclear antibody test (ANA) to look for other types of arthritis or illness.
- A genetic test, which may be done to determine the presence of a gene (HLA-B27) that is often linked with ankylosing spondylitis. Many people who have the HLA-B27 gene will not develop ankylosing spondylitis, so having this test will not confirm whether you have the condition. But the test results can be helpful if your symptoms and physical exam have not clearly pointed to a diagnosis.
Treatment for ankylosing spondylitis focuses on relieving pain and stiffness, reducing inflammation, keeping the condition from getting worse, and enabling you to continue daily activities. Early diagnosis and treatment may reduce pain, stiffness, inflammation, and deformity.
Talk with your doctor about the best treatment approach for your condition. A consultation with a rheumatologist is often recommended, especially to confirm the diagnosis and lay out a treatment plan. Your family medicine physician or internist can treat mild cases. Or you may be referred to a rheumatologist, orthopedist, or physiatrist.
Initial treatment for ankylosing spondylitis may include:
- Education, so you know what you can expect as ankylosing spondylitis progresses and how you can minimize problems that can be caused by your condition.
- Flexibility and strengthening exercises, to maintain mobility and control pain. People who exercise regularly find they have less pain and stiffness than those who are less active.
- Nonsteroidal anti-inflammatory drugs (NSAIDs), to relieve pain and stiffness, reduce inflammation, and help with physical therapy. Some people seem to get more benefit from daily NSAIDs than from taking NSAIDs just when they notice symptoms. Talk to your doctor about using NSAIDs for ankylosing spondylitis, including how much to take and how often to take it.
- Physical therapy, to help you keep proper posture, and deep breathing exercises, to enhance your lung capacity. A physical therapist can also help you learn to use heat and cold to help control your pain and stiffness. Heat can help with relaxation and pain relief, and cold can help reduce inflammation.
- Assistive devices such as canes or walkers, which allow you to be physically active while reducing stress on joints.
- Alternative therapies such as yoga or acupuncture, which may help relieve pain and improve quality of life.
Talking with your doctor about your job. A job that is physically demanding—such as a job that requires lots of heavy lifting—could increase your symptoms.
If initial treatment does not sufficiently reduce the pain and inflammation linked with ankylosing spondylitis, and as your condition progresses, ongoing treatment may include:
- Flexibility and strengthening exercises, to maintain mobility and control pain. People who exercise regularly find they have less pain and stiffness than those who are less active. In addition to general flexibility and strengthening, walking and swimming are good activities for people who have ankylosing spondylitis. Some people continue to participate in sports also. Talk to your doctor or physical therapist about activities that will help you and that you will enjoy.
- Medicine. Doctors usually will first recommend nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation. But you may need other, stronger medicines. Be safe with medicines. Read and follow all instructions on the label.
- Corticosteroids, which are similar to natural hormones produced in the body, help reduce inflammation. Corticosteroids are sometimes used for joints such as the hips, not for the joints of the spine.
- Disease-modifying antirheumatic drugs (DMARDs). Non-biologic DMARDs, such as methotrexate or sulfasalazine, may help relieve pain in joints other than the spine and pelvis. Biologic DMARDS, such as etanercept or infliximab, reduce inflammation by blocking harmful responses from the body's immune system that lead to the symptoms of ankylosing spondylitis.
- Physical therapy, to help you keep good posture, and deep breathing exercises, to enhance your lung capacity. A physical therapist can also help you learn to use heat and cold to help control your pain and stiffness. Heat can help with relaxation and pain relief, and cold can help reduce inflammation.
- Assistive devices such as canes or walkers, which allow you to maintain physical activity while reducing stress on joints.
- Alternative therapies such as yoga or acupuncture, which may help relieve pain and improve quality of life.
Your doctor will treat complications of ankylosing spondylitis as they occur. For example, iritis may be treated with medicines that can help reduce inflammation of the eye, such as corticosteroids and mydriatic eyedrops.
Treatment if the condition gets worse
In rare cases, you may need surgery to replace joints that are severely damaged by the inflammation of ankylosing spondylitis. The most common surgery done is hip replacement surgery. Spine surgery is done in a very small number of people who have ankylosing spondylitis. If there is loosening of the top two vertebrae in the neck and there are signs of pressure on the spinal cord such as numbness or clumsiness in the hands or arms, a surgeon may permanently join (fuse) the two vertebrae together. In very rare cases, spinal surgery may be done to straighten a part of the spine that has become severely curved, but the surgery is risky and cannot restore motion.
Because ankylosing spondylitis is a lifelong condition, other treatment may include complementary therapies, which can reduce symptoms, help manage pain, and improve quality of life. These therapies may include yoga and acupuncture.
Even if your symptoms are under control, you should see your doctor (often a rheumatologist) every year to watch for and treat any complications. People with hip symptoms and perhaps those whose disease started in their teens may be at risk for a more severe progression of ankylosing spondylitis.
If you have been diagnosed with ankylosing spondylitis, there are steps that you can take at home to help reduce pain and stiffness and allow you to continue daily activities. These steps include:
- Educating yourself. Learn all you can about your condition and know what complications to watch for. This will help you control your symptoms and stay more active.
- Taking pain relievers such as nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain. If NSAIDs do not relieve your pain, try acetaminophen. Heat, such as warm showers or baths or sleeping under a warm electric blanket, may also reduce pain and stiffness.
Exercising regularly. This reduces pain and stiffness and helps maintain fitness and mobility of the spine, chest, and joints. Your doctor may recommend physical therapy to get you started on an exercise program.
- Deep breathing exercises can improve or help you keep your lung capacity.
- Swimming as part of your exercise program helps to maintain chest expansion and movement of the spine without jarring the spine. Breaststroke is especially good for chest expansion.
- You should avoid contact sports, because joint fusion may make your spine more likely to fracture as the disease progresses. Your doctor may approve of other activities such as golf and tennis. Check with your doctor before you add any new activity.
- Maintaining proper posture and chest expansion. Good posture is important because it can help prevent abnormal bending of the spine. Maintaining chest expansion may help prevent problems such as lung infection (pneumonia). It's a good idea to lie on your stomach a few times each day to keep your spine and hips extended. For sleeping, choose a firm mattress and a small pillow that supports your neck. Try to lie flat on your back to sleep. If it's comfortable for you, you can also sleep part of the night on your stomach.
- Using assistive devices such as canes or walkers. Your local chapter of the Arthritis Foundation, your physical therapist, or a medical supply company may be able to help you find assistive devices in your area.
- Taking steps to protect yourself in the car, such as always using a seat belt. Joints that are inflamed or damaged can easily be injured in an accident. If your neck is becoming stiff, your doctor may advise you to wear a soft neck brace when you ride in the car, to prevent injury in case of an accident.
- Avoiding smoking, to prevent serious breathing problems and lung scarring. Lung damage from smoking, combined with decreased chest expansion and the lung infections that sometimes go with ankylosing spondylitis, can seriously limit your ability to breathe freely.
- Seeing your doctor (often a rheumatologist) at least once each year, to check on your condition and watch for any complications. Catching complications early and treating them can prevent further problems.
- Having regular eye exams by an ophthalmologist, to check for inflammation of the colored part of the eye (iritis).
- Talking with your doctor about your job. A job that is physically demanding—such as a job that requires lots of heavy lifting—could increase your symptoms.
- Joining a support group. Ask your doctor about the types of support that are available where you live. Meeting other people with the same problems can help you know that you're not alone.
Other Works Consulted
- Deimel GW IV, Braverman SE (2015). Ankylosing spondylitis. In WR Frontera et al., eds., Essentials of Physical Medicine and Rehabilitation, 3rd ed., pp. 609–613. Philadelphia: Saunders.
- Inman RD (2016). The spondyloarthropathies. In L Goldman, A Shafer, eds., Goldman-Cecil Medicine, 24th ed., vol. 2, pp. 1762–1769. Philadelphia: Saunders.
- Van der Linden SM, et al. (2013). Ankylosing spondylitis. In GS Firestein et al., eds., Kelley's Textbook of Rheumatology, 9th ed., vol. 2, pp. 1202–1220. Philadelphia: Saunders.
- Ward MM, et al. (2016). American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network 2015 recommendations for the treatment of ankylosing spondylitis and nonradiographic axial spondyloarthritis. Arthritis and Rheumatology, 68(2): 282–298. DOI: 10.1002/art.39298. Accessed April 29, 2016.
Current as of: August 5, 2020
Author: Healthwise Staff
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Martin J. Gabica MD - Family Medicine
Kathleen Romito MD - Family Medicine
Richa Dhawan MD - Rheumatology
To learn more about Healthwise, visit Healthwise.org.
© 1995-2021 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.