What is ankylosing spondylitis?

Ankylosing spondylitis is characterized as a type of chronic inflammation that primarily affects the spine and the sacroiliac joints, which are located at the lower back where the spine meets the pelvis. This condition leads to pain and stiffness in the back, and over time, it can result in the fusion of vertebrae, which severely limits flexibility and can lead to a stooped posture.

The chronic inflammatory nature of the disease is critical; it involves autoimmune processes that can cause the body to mistakenly attack its own tissues, particularly those in the joints. The specific involvement of the sacroiliac joints is a key feature as they are often among the first areas affected, leading to significant discomfort and mobility issues.

Understanding this condition requires recognizing its impact on the musculoskeletal system, particularly how it differs from other forms of arthritis or joint inflammation that may not primarily target the spine.