Ankylosing spondylitis (AS) is a chronic type of arthritis affecting the spine and sacroiliac joints, located in the lower back. Its name comes from Greek, with “ankylos” meaning joint stiffening and “spondylo” referring to vertebrae. Apart from the spine and sacroiliac joints, AS can also affect other joints like shoulders, ribs, hips, knees, and feet. Inflammation can extend to tendons and ligaments, sometimes involving organs like the eyes, bowel, and rarely the heart and lungs.
AS causes inflammation in spinal joints, resulting in redness, heat, swelling, and pain. Chronic inflammation leads to stiffness and pain around the spine. As the disease progresses, spinal fusion (ankylosis) can occur, causing the spine to fuse in a fixed position, often leading to a forward-stooped posture called kyphosis.
AS typically begins in the teen or young adult years, with symptoms appearing before age 30 in most cases. It’s more common in men, with symptoms ranging from mild to severe. Back pain is the primary symptom, initially mild but potentially worsening over time. Other joints like hips, knees, ankles, and shoulders can also become painful, stiff, and swollen. General symptoms may include fatigue, weight loss, or anemia. Chronic inflammation and spinal fusion can limit breathing capacity and scar the lungs, leading to coughing and shortness of breath, especially during exercise or infection.
The exact cause of AS is unknown, and there’s no known prevention or cure. However, treatments and medications can manage symptoms and pain. Newer therapies, such as biologic medications, may slow or halt disease progression in some individuals.