Ankylosing spondylitis is a type of arthritis that mainly affects the spine and lower back. Over time, the symptoms can begin to affect other parts of the body.
Ankylosing spondylitis (AS) causes inflammation in the joints of the spine, which can lead to severe, chronic pain. In advanced cases, it can cause bones to fuse in the spine, leading to a loss of mobility.
Over time, AS may begin to affect other joints in the body, including the ribs, neck, knees, and feet. In very rare cases, people may have complications involving their heart or lungs.
Treatment can slow or halt the progression of AS, and certain exercises can help people manage their symptoms, relieve pain, and avoid complications.
In this article, we examine how AS affects the body over time, how to treat and manage these effects, and the outlook for people with this condition.
According to the Spondylitis Association of America (SAA), in its early stages, AS most commonly affects the spine, causing frequent pain and stiffness in the lower back.
The symptoms of AS are due to inflammation in the joints and are not related to any mechanical cause in the early stages. They tend to come on gradually over several weeks or months. The symptoms are usually worse in the morning and after rest, but light exercise or a warm shower can often relieve pain and stiffness.
Spondylitis is another word for “spine inflammation,” and ankylosing means “stiffening.” Put together, ankylosing spondylitis refers to spinal stiffness resulting from inflammation and the fusion of bones.
As the inflammation travels up the spine, it can affect the person’s posture. If the spinal bones, called vertebrae, begin to fuse, the person may lose flexibility in their spine, resulting in decreased mobility and changes in posture.
The bones fuse due to calcium deposits appearing around the ligaments and the disks between the vertebrae. These deposits occur as a result of the bones healing from the inflammation. Spinal fusion leaves the vertebrae brittle and prone to fractures, and it can result in kyphosis, a forward curving of the spine.
Controlling inflammation early — by taking the appropriate medications and doing certain stretches and exercises — can help delay the progression of AS and stop it from spreading further up the spine or to other body parts.
In the early stages, AS symptoms often remain confined to the spine and lower back. They primarily affect the sacroiliac joint, which is where the spine and pelvis join.
Over a longer period, however, stiffness and pain can spread up the spine and into the neck. This spread may occur over the course of several months or years.
AS-related inflammation may also affect other organs, such as the eyes, heart, and lungs.
Each person has a unique experience with AS. The body parts that it affects and the progression of the disease are different for everyone. Some people will experience only mild symptoms with no complications, but, in rare cases, a person may develop life-threatening complications.
The following sections reveal how AS can affect body parts other than the spine.
The sacroiliac joint is the joint that AS primarily affects, but as the condition progresses, it can affect any joint in the body.
Symptoms in all affected joints include joint pain, stiffness, and swelling.
AS causes inflammation of the tissue lining the inside of the joints, called the synovial membrane. This joint inflammation is known as synovitis.
While symptoms of AS can appear in any joint, they are most common in the larger joints of the body.
Symptoms of AS may arise in the following joints:
- shoulder blades
AS affects the hip and shoulder joints in approximately one-third of people with the condition.
One hallmark of AS is inflammation in the spot where the ligament attaches to the bone. Inflammation here is known as enthesitis.
The effects of enthesitis are particularly significant in the foot and can affect mobility. The two main affected areas are the Achilles tendon and the base of the heel.
In approximately 15% of people, the inflammation affects the temporomandibular (TMJ) joint, causing jaw pain and difficulty chewing or swallowing.
Inflammation from AS can spread up the spine and affect the chest because the ribs are attached to the vertebrae. Here, it can cause chest pain and trouble breathing. When inflammation causes stiffness in the ribs, it is more difficult for the chest to expand when a person inhales.
The result is a feeling of air hunger or tightness in the chest. People may feel as though their breaths are inadequate as the lungs struggle to expand in a tight ribcage.
If the disorder progresses, the ribs may become fused to the spine, making these symptoms worse.
Practicing deep breathing exercises after a shower or using ice packs on the ribs can help. Learning how to do diaphragmatic breathing may also be beneficial.
Inflammation in the eye, known as iritis or uveitis, is common with AS. Eye inflammation affects about one-third of people with AS at least once during the course of their disease.
People may experience the following eye-related symptoms:
- eye pain or pressure
- increased sensitivity to light, known as photophobia
- watery, bloodshot eyes
- seeing dark spots
- blurred vision
Many people with AS experience inflammation in the bowel, which is associated with inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis.
As a result of the spinal involvement and subsequent neurological complications, AS can reduce a person’s ability to control urination or bowel movements, leading to incontinence.
Heart and lung complications from AS are very rare.
When they occur, the person may experience an irregular heartbeat or an inflamed aorta, which is the main artery from the heart.
Some people with AS develop sleep apnea, meaning that their breathing repeatedly stops during sleep.
In some cases, lung tissue may develop scarring, lesions, or cysts.
Some people may have a functional lung impairment, meaning that it can take longer for respiratory infections and colds to heal.
While there is no cure for AS, various treatments can slow or halt its progress. Treatment plans generally include regular medication and exercises.
Eating a varied and nutritious diet, using hot and cold packs to relieve pain, and avoiding smoking can benefit the overall management of AS and should be part of all treatment plans.
Doctors often recommend nonsteroidal anti-inflammatory drugs (NSAIDs) to manage AS-related inflammation.
Other drug options include:
- pain relievers
- disease-modifying antirheumatic drugs (DMARDs), such as sulfasalazine and methotrexate
- local injections of corticosteroids
- anti-tumor necrosis factor drugs, such as adalimumab, certolizumab, etanercept, golimumab, and infliximab
- other biologic treatments, such as secukinumab
Most people do not need surgery, but it is an option if the pain is severe or persistent or significantly impairs the person’s mobility or quality of life.
Read more about drug treatments for AS here.
For back pain associated with AS, physical therapy, such as stretching and mobility exercises, can help reduce pain and stiffness. Experts recommend doing these exercises every day.
The SAA recommend that AS exercise programs include the following four elements:
- Stretching: Range-of-motion stretches improve flexibility and reduce muscle stiffness, swelling, and pain.
- Cardiovascular exercise: Aerobic activity, such as swimming and walking, can help reduce pain and fatigue, as well as improving lung and heart function.
- Strength exercises: Strong muscles, especially in the core and back, can improve posture and reduce pain.
- Balance training: By working on their balance, people can improve their stability and reduce their risk of falls.
Each person’s experience with AS is unique. The severity and location of the symptoms and the disease progression vary widely among individuals.
AS is a progressive disease. Without treatment, the symptoms may spread and worsen. Chronic pain and loss of flexibility are problems for many people with untreated AS, and they can lead to physical disability.
Long-term untreated inflammation can cause many complications, including an increased risk for heart disease, gut disorders, and extreme tiredness.
Some people only experience mild symptoms, while others will have chronic symptoms that continue to worsen. Life threatening complications are rare.
Remission is possible, with approximately 1% of people reaching a stage of lower levels of disease activity with less inflammation and fewer physical limitations.
Lifestyle factors can affect a person’s outcome. For instance, following an AS-specific exercise program, ensuring good nutrition, and avoiding smoking are linked with better outcomes.
Working directly with a doctor or rheumatologist, people with AS can usually create a treatment plan that helps keep the disorder in check. Once the plan is in place, following it carefully will help prevent the condition from progressing.
AS is a type of arthritis that primarily affects the spine and lower back. Over time, however, the condition can spread to other joints.
The inflammation that the condition causes can also affect the organs, including the eyes and bowel, and, in rare cases, the heart and lungs.
People with AS can prevent disease progression by taking medications as prescribed, doing a range of exercises, and making certain lifestyle changes.