The most common complaint in ankylosing spondylitis is chronic pain and stiffness. This pain and stiffness is usually experienced in the lower back, hips, and buttocks, but it can also occur in other areas of the body such as the neck, shoulders, and chest. The pain and stiffness can range from mild to severe, and it is often worse in the morning or after periods of inactivity. Other common complaints associated with ankylosing spondylitis include fatigue, difficulty sleeping, difficulty with everyday activities, and stiffness that can last for hours or even days. In some cases, the pain and stiffness can be so severe that it prevents the person from participating in normal activities. As the disease progresses, it can lead to an increased risk of inflammation, bone fusion, and deformity. Furthermore, it can cause respiratory problems due to the involvement of the ribcage.