Overview of Ankylosing Spondylitis

Ankylosing spondylitis is a type of arthritis that causes inflammation in the joints and ligaments of the spine. Normally, the joints and ligaments in the spine help us move and bend. If you have ankylosing spondylitis, over time, the inflammation in the joints and tissues of the spine can cause stiffness. In severe cases, this may cause the vertebrae (bones in the spine) to fuse (grow together). When the vertebrae fuse, it can lead to a rigid and inflexible spine. (For more information about the anatomy of the spine, see our Back Pain Health Topic.)

Many people with ankylosing spondylitis have mild episodes of back pain and stiffness that come and go. But others have severe, ongoing pain with loss of flexibility in the spine. In addition, other symptoms may develop if other areas of the body—such as the hips, ribs, shoulders, knees, ankles, and feet—are affected by the disease.

There is no cure for ankylosing spondylitis. Doctors recommend treatments that may include exercise and medications to help manage pain, control inflammation, improve posture and body position, and slow the progression of the disease. With treatment, most people with ankylosing spondylitis can have productive lives.

Who Gets

Who Gets Ankylosing Spondylitis?

Anyone can get ankylosing spondylitis; however, certain factors may increase your risk for developing the disease. These factors include:

  • Family history and genetics. If you have a family history of ankylosing spondylitis, you are more likely to develop the disease.
  • Age. Most people develop symptoms of ankylosing spondylitis before age 45.   However, some people develop the disease when they are children or teens.
  • Sex. Men are more likely to have ankylosing spondylitis than women.
  • Other conditions. People who have Crohn’s disease, ulcerative colitis, or psoriasis may be more likely to develop the disease.


Symptoms of Ankylosing Spondylitis

The most common symptom of ankylosing spondylitis is lower back and/or hip pain and stiffness. Over time, the symptoms may progress to other areas of the spine. The pain typically worsens during periods of rest or inactivity, which may cause some people to experience more pain during the middle of the night or after prolonged sitting. Usually, moving and exercise can help improve pain. 

Symptoms of ankylosing spondylitis vary from person to person. Some people have mild episodes of pain that come and go, while others will have chronic, severe pain. The symptoms of ankylosing spondylitis, whether mild or severe, may worsen in “flares” and improve during periods of remission. 

Because the disease can affect other areas of the body, other symptoms may develop and may include:

  • Pain, stiffness, and inflammation in other joints, such as the ribs, shoulders, knees, or feet.
  • Difficulty taking deep breaths if the joints connecting the ribs are affected.
  • Vision changes and eye pain due to uveitis, which is inflammation of the eye.
  • Fatigue, or feeling very tired.
  • Loss of appetite and weight loss.
  • Skin rashes.
  • Abdominal pain and loose bowel movements.


Causes of Ankylosing Spondylitis

Researchers do not know the cause of ankylosing spondylitis. However, studies show that both genes and environment may lead to the development of the disease. Researchers know that the HLA-B27 gene increases the risk of developing ankylosing spondylitis, but this does not mean you will get the disease if you have the gene. Many people have the gene and never develop ankylosing spondylitis, which tells researchers that environmental factors also play a role.  

Researchers continue to discover many other gene variations that may cause the disease; however, HLA-B27 is the primary gene that increases your risk for developing ankylosing spondylitis.


Diagnosis of Ankylosing Spondylitis

To diagnose ankylosing spondylitis, your doctor will ask you about your medical history and perform a physical exam. Your doctor may order imaging studies and lab tests to help confirm a diagnosis.

Medical and Family History

Your doctor may ask about your medical and family history, including questions such as:

  • How long have you had pain?
  • Where is your pain?
  • What makes the pain better or worse?
  • Does anyone in your family have a history of back pain, joint pain, or arthritis?

Physical Exam

A physical exam may include:

  • Examining your joints, including your spine, pelvis, heels, and chest.
  • Watching how you move and bend in different directions, checking for flexibility.
  • Asking you to breathe deeply to check for rib stiffness and inflammation. 

Imaging Studies

Your doctor may order imaging studies to help diagnose ankylosing spondylitis:

  • X-rays help doctors see joint changes. However, you may have the disease for years before the changes show on x-rays. Doctors may use x-rays to monitor the progression of the disease or to rule out other causes for the joint pain.
  • Magnetic resonance imaging (MRI) uses energy from a powerful magnet to produce signals that create a series of cross-sectional images. These images or “slices” are analyzed by a computer to produce an image of the joint. MRI can help diagnose ankylosing spondylitis in the early stages of the disease.

Your doctor may use both x-rays and MRIs to follow the progression of your disease.

Lab tests

At this time, no single test diagnoses ankylosing spondylitis. Your doctor may order a blood test to check for the HLA-B27 gene, which is present in most people with the disease. You may have the HLA-B27 gene and never develop ankylosing spondylitis, but it can give doctors more information when making a diagnosis. 


Treatment of Ankylosing Spondylitis

There is no cure for ankylosing spondylitis; however, your doctor will work with you to help manage the disease. The goals of treatment include:

  • Relieve symptoms.
  • Help maintain proper posture.
  • Slow the progression of the disease.

In most cases, treatment includes medication and physical therapy. Sometimes, people with severe disease need surgery to repair joint damage.


Most people with ankylosing spondylitis take medications, which may include one or more of the following:

  • Over-the-counter anti-inflammatory medications to relieve pain and inflammation are commonly used to treat ankylosing spondylitis.
  • Biologic medications target specific immune messages and interrupt the signal, helping to decrease or stop inflammation. These medications may be prescribed if your disease is unresponsive to other treatments.  
  • Corticosteroids can help decrease inflammation and provide some pain relief. They are usually injected into the joint. Because they are potent drugs, your doctor will determine how much and how many injections you should receive to achieve the desired benefit.

Physical Therapy

Your doctor may recommend physical therapy to help:

  • Relieve pain.
  • Strengthen back and neck muscles.
  • Improve core and abdominal muscle strength because these muscles provide support for your back.
  • Improve posture.
  • Maintain and improve flexibility in joints.

A physical therapist can recommend the best sleeping positions and an exercise program. Because your symptoms may worsen when inactive or at rest, it’s important to stay active and exercise regularly.    


If you have severe joint damage and you are unable to participate in your daily activities, your doctor may recommend surgery. Surgery is not for everyone. You and your doctor can discuss the options and choose what is right for you.

Your doctor will consider the following before recommending surgery:

  • Your overall health.
  • The condition of the affected bone or joint.
  • The risks and benefits of the surgery.

Types of surgery may include joint repairs and joint replacements.

Rarely, some people may have surgery to correct or straighten the spine or repair fractures (breaks) in the vertebrae.

Who Treats

Who Treats Ankylosing Spondylitis?

Diagnosing and treating ankylosing spondylitis may require a team of health care professionals.  These may include:

  • Rheumatologists, who specialize in arthritis and other diseases of the bones, joints, and muscles.
  • Dermatologists, who specialize in conditions of the skin, hair, and nails.
  • Gastroenterologists, who specialize in conditions of the digestive system.
  • Mental health professionals, who help people cope with difficulties in the home and workplace that may result from their medical conditions.
  • Nurse educators, who specialize in helping people understand their overall condition and set up their treatment plans.
  • Occupational therapists, who teach ways to protect joints, minimize pain, perform activities of daily living, and conserve energy.
  • Ophthalmologists, who specialize in conditions of the eye.
  • Orthopaedic surgeons, who specialize in treatment and surgery for bone and joint diseases.
  • Physiatrists (physical, medicine, and rehabilitation specialists), who supervise exercise programs.
  • Physical therapists, who help improve joint function.
  • Primary care doctors, such as a family physician or internal medicine specialist, who coordinates care between the different health providers and treats other problems as they arise.
  • Psychologists or social workers, who help with psychosocial challenges caused by medical conditions.

Living With

Living With Ankylosing Spondylitis

Research shows that people who take part in their own care report less pain and make fewer doctor visits. They also enjoy a better quality of life.

Self-care can help you play a role in managing your ankylosing spondylitis and improving your health. You can:

  • Learn about the disease and its treatments.
  • Communicate well with your health care team so you can have more control over your disease.
  • Reach out for support to help cope with the physical, emotional, and mental effects of ankylosing spondylitis.

Participating in your care can help build confidence in your ability to perform day-to-day activities, allowing you to lead a full, active, and independent life.

The following lifestyle changes and activities can help improve your ability to function on your own and maintain a positive outlook.

  • Exercise. Exercise is important for maintaining healthy and strong muscles, preserving joint mobility, and maintaining flexibility. In addition to an exercise program, your doctor may recommend low-impact exercises, such as water exercise programs. Talk to your health care providers before beginning any exercise program. Exercise can help:
    • Improve your sleep.
    • Decrease pain.
    • Keep a positive attitude.
    • Maintain a healthy weight.
  • Posture. Another important thing you can do for yourself is to practice good posture. Your physical therapist and doctors can give you tips and exercises to help maintain and improve your posture. Practicing good posture can help you avoid some of the complications that can occur with ankylosing spondylitis.
  • Support or assistive devices. Using a cane or walker can help you move around safely, provide stability, and lower pain. If you have trouble bending due to spine stiffness, try using a device to grab or pick up items.
  • Monitoring of symptoms. It is important to monitor your symptoms for any changes or the development of new symptoms. Understanding your symptoms and how they may change can help you and your doctor manage your pain when you have a flare.
  • Stress management. The emotions you may feel because of your disease, along with any pain, physical limitations, and the unpredictable nature of flares, can increase your stress level. Although there is no evidence that stress plays a role in your disease, it can make living with ankylosing spondylitis more difficult. Ways to cope with stress can include:
    • Use relaxation techniques such as deep breathing, meditating, or listening to quiet sounds or music.
    • Try movement exercise programs, such as yoga and tai chi.
  • Mental health management. If you feel alone, anxious, or depressed about having ankylosing spondylitis, talk to your doctor or mental health professional. Keep the lines of communication open. Talk to family and friends about your disease. You may find it helpful to join an online or community support group.
  • Healthy diet. A healthy diet is good for everyone, and it may be very helpful if you have ankylosing spondylitis. There is no specific diet for people with ankylosing spondylitis, but keeping a healthy weight is important. It reduces stress on painful joints.
  • Smoking. If you smoke, quit. Ankylosing spondylitis is more severe in people who smoke, and smoking blunts the effect of treatment. In addition, if you have ankylosing spondylitis in the chest or ribs, smoking can compromise your lung function even more. Smoking is also a risk factor for progression of disease.

Research Progress

Research Progress Related to Ankylosing Spondylitis

The NIAMS conducts translational and clinical research on the causes and treatment of ankylosing spondylitis. In addition, the NIAMS funds and supports many researchers at universities and other organizations throughout the country who are studying the disease.

Over the last several decades, NIAMS-funded research has greatly increased our understanding of genetics and ankylosing spondylitis, including:

  • The discovery of the relationship between ankylosing spondylitis and the HLA-B27 gene, the primary gene involved in the development of the disease.
  • The discovery of genes and genetic markers that help scientists understand more about how ankylosing spondylitis develops. These findings can help researchers develop more effective treatments.
  • Genetic influences that are associated with risk for ankylosing spondylitis.

Current research focuses on investigating:

  • Genetic factors and risks that may influence the severity of the disease.
  • How alterations and changes in the immune system are associated with the development of ankylosing spondylitis.
  • How the environment and genetics interact and affect the course of the disease.
  • If computed tomography (CT) scanning can help monitor the disease.
  • New and current medications to treat the disease more effectively.
  • The impact of exercise and physical therapy interventions on ankylosing spondylitis. 

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