Ankylosing spondylitis (AS) is a form of inflammatory arthritis that affects the joints of the lower back, which become inflamed and stiff. In severe cases, the spine joints can become fused (join together) and lose their movement.
Ankylosing spondylitis usually starts around the triangular bone at the base of the spine (the sacrum), where it joins the pelvis (in the sacroiliac joint). These joints become painful and inflamed, causing lower back stiffness, particularly in the morning.
The spine is made up of a chain of bones called vertebrae. Inflammation starts at the edges of the vertebral joints, leading to scar tissue forming in the space between the bones, making the joint stiff. The scar tissue may then turn to bone, filling the space between the bones and effectively fusing the joint. Movement of the spine is then limited. AS tends to be more common in young men but it also occurs in young women. Like most kinds of inflammatory arthritis, it can go into remission.
AS usually affects the joints of the spine, shoulders and, sometimes, the hips. In a few people, other joints can also be affected, such as the knees and ankles.
How will it affect me?
AS starts with pain, aching and stiffness, usually in the lower back. After a while the pain will go, before reappearing, maybe further up the back. Movement of the chest may become limited. These bouts of pain and stiffness are likely to come and go over a number of years and, then, when the inflammation dies down, they may stop altogether, though the restriction of movement in the spine and chest persists.
Most people with AS have some pain and discomfort but manage a full and normal daily routine. For others, with more severe AS, the spinal restriction and inflammation in other joints can become severe and disabling. With an early As with other inflammatory diseases there can be bouts of overwhelming fatigue with AS.
In addition, there is a risk of developing an inflammation called iritis, which affects the eyes. If you find your eyes become painful and bloodshot, you should speak to your doctor immediately.
How is it treated?
Anti-inflammatory drugs can help to reduce the pain and stiffness of AS. There can be an inclination to rest when feeling unwell with any form of arthritis, but exercise will help to relieve pain of AS, maintain mobility and prevent the joints from becoming fused into a bad position.
If it is your hip joints that are affected, then joint replacement surgery could be considered. Ask your doctor about your options. Most people with AS will respond positively to treatment with anti-inflammatory drugs and physiotherapy, but biologic drugs can also be used. Speak to your rheumatologist about whether you could be a suitable candidate for this form of treatment.