Ankylosing spondylitis (AS) is a form of arthritis that mainly affects the spine, lower back, and sacroiliac joints.
AS is an inflammatory condition. Characteristic symptoms include joint pain, stiffness, and a loss of mobility in the spine and lower back.
The condition involves inflammation where the ligament and tendons attach to the bones of the spine and the bones of the peripheral joints, known as the entheses.
This inflammation results in increased bone formation in the spine, leading to bone fusion. In advanced cases, this can also lead to spinal deformity.
Drug treatments and physical therapy can help relieve the symptoms.
This article explains AS, including its symptoms, treatments, causes, complications, and associated exercises.
AS can be challenging to diagnose, but it has a particular pattern of pain symptoms, and the changes are usually visible in X-ray and MRI scans.
However, symptoms can also develop in children and people who are much older.
There is currently no cure for AS, but certain drugs can help manage pain and inflammation. Physical therapy can relieve pain and prevent or delay limitations and decreased mobility.
The most common early symptoms of AS are frequent pain and stiffness in the lower back, the hip area, or both. These symptoms may occur over several weeks or months.
Over time, these symptoms may spread to other areas of the spine and can affect the neck’s spinal joints.
Some people have mild pain that comes and goes, while others have severe, long lasting pain. Everyone with AS is likely to experience flares — when the symptoms worsen — and periods of remission where symptoms improve.
The main symptoms of AS affect the spine and lower back,
The pain usually worsens at rest and during the night and can interfere with restorative sleep. Moving around can generally improve pain levels.
However, AS can also affect other parts of the body. These include the areas around other joints, such as the:
- ankles, feet, and tendon insertions at the heel
- top of the shin bone in the lower leg
- Achilles tendon
AS is a systemic condition. People can experience fatigue, which refers to a feeling of being tired and lacking energy.
Treatment options include:
People with a diagnosis of AS will need to consult a specialist doctor known as a rheumatologist. They may need several visits as the condition progresses slowly, and consistent medical care allows better monitoring and treatment.
Doctors will only recommend surgery to correct severe deformities, such as excessive posture changes due to inflammation and ankylosing of the spine, or replace a hip or other joint.
Doctors might also recommend certain diets, foods, or nutrients to help a person manage the symptoms of AS.
Acetaminophen and codeine are also options if NSAIDs are unsuitable or ineffective.
Some NSAIDs compromise bone health by reducing the creation of new bone, so doctors do not usually recommend NSAIDs after surgery for people with bone fusion problems.
Some other drug options and their examples include:
- Corticosteroids: Local steroid injections that can provide quick pain relief.
- Disease-modifying antirheumatic drugs (DMARDs): Sulfasalazine (Azulfidine, Sulfazine) and methotrexate (Otrexup, Rheumatrex, or Trexall).
- Other biologic treatments: Secukinumab (Cosentyx).
- Tumor necrosis factor antagonists:
AS can affect the whole body, and a person
To diagnose AS, a doctor
If inflammatory back pain is present with certain features, it may indicate AS.
- pain that does not improve with rest
- pain that causes sleep disturbance
- back pain that starts gradually, between the ages of 17 and 45 years, and is not due to injury
- symptoms that persist for several months
- spinal stiffness in the mornings, which seems to improve with exercise and motion
Imaging tests for AS may confirm the diagnosis, but changes may not be immediately visible on such tests. This can delay diagnosis.
The section below examines blood and imaging tests in more detail.
No blood test can confirm AS, but some tests can rule out other causes of the person’s symptoms.
The tests for inflammation
These may include:
The exact cause of AS remains unclear, but the early symptoms result from inflammation in parts of the lower spine.
AS may have genetic and environmental components.
In severe cases, AS
In some cases, AS can also restrict the movement of the chest and make it difficult to breathe.
Other rarer complications of the condition
- Aortic regurgitation: Where the heart’s aortic valve does not close tightly.
- Pulmonary fibrosis: A type of lung disease where the tissue is damaged or scared.
- Cauda equina syndrome: A complication where the nerves in the back become severely compressed.
Chronic pain and symptoms associated with AS can cause people to experience depression and other mood disorders.
Although living with AS can present challenges, there are many ways that people can adapt to living with the condition.
According to the
There are many ways that people can practice self-care, including:
- learning about the disease and its treatments
- seeking support for the physical and mental effects of AS
- communicating with health teams to enable the best care for their condition
People can also try numerous lifestyle changes and activities to improve function and increase their understanding and autonomy over their condition. These include:
- using support and assistive devices
- maintaining good posture
- monitoring symptoms
- following a healthy diet
- managing stress
- stopping smoking
- receiving mental health support, such as therapy
The SSA offers further resources and support for people living with AS, including support groups, educational resources, and community forums.
Physical therapy and exercises can help treat the symptoms and prevent or delay mobility limitations.
A physical therapist will be able to design a program that can help a person maintain good posture and motion in the joints.
This might consist of the following:
- daily exercises
- special training to address areas of involvement
- therapeutic exercises
Physical therapy exercises are known as strengthening exercises and range-of-motion exercises.
The SSA notes that an ideal exercise program will include the following four elements:
- Stretching: This can improve flexibility and reduce muscle stiffness, swelling, and pain. It can also minimize the risk of joint fusion.
- Cardiovascular exercises: These exercises include swimming and walking. They can improve lung and heart function and reduce pain and fatigue.
- Muscle exercises: These help strengthen the core and back muscles, which help support the spine. Having strong muscles can improve posture and movement, as well as reduce pain.
- Balance training: This can help improve stability and reduce the risk of falls.
The outlook for AS is difficult to predict because it varies widely from person to person, and the progression is often not constant. Important factors for measuring outlook include levels of functional ability, spinal mobility, and joint damage.
Some people experience severe functional loss, while others hardly notice their symptoms. Around 1% of people experience long-term remission, wherein symptoms cease to develop. In contrast, some people may have life threatening complications that affect the heart, lungs, or nervous system.
Smoking can lead to poorer outcomes.
AS is a type of arthritis that affects the spine and lower back. It is most common in males and tends to appear in late adolescence or early adulthood.
Although there is currently no cure for AS, many treatments can help slow or stop the progression. Daily management, such as an exercise program, can help people control their symptoms.