What is a key characteristic of Ankylosing Spondylitis?

Ankylosing Spondylitis is primarily characterized by chronic inflammation of the spine. This condition predominantly affects the spine and the sacroiliac joints, leading to symptoms such as pain and stiffness in the back and hips, especially noticeable during rest periods and improving with movement. Over time, the inflammation can result in significant changes, including the fusion of the vertebrae, which may lead to a stooped posture—a hallmark of the disease.

While damage to peripheral joints can occur, it is not the defining characteristic of Ankylosing Spondylitis, as the condition is primarily axial, focusing on the spine. Random joint swelling is not characteristic of this disease either; Ankylosing Spondylitis typically has a more predictable pattern of symptoms. Rapid onset muscle atrophy is also not associated with this condition; while muscle atrophy can occur due to disuse or inactivity related to pain, it is not a direct characteristic of the disease itself. Therefore, chronic inflammation of the spine is the most accurate defining feature of Ankylosing Spondylitis.