Ankylosing spondylitis (AS) is a chronic inflammatory disorder that primarily affects the axial skeleton, leading to progressive spinal rigidity, pain, and functional impairment. As the prototypic form of axial spondyloarthritis (axSpA), AS is closely associated with the HLA-B27 allele; however, its pathogenesis reflects a multifactorial interaction involving genetic susceptibility, immune dysregulation, and environmental influences. Key immune pathways include the IL-23/IL-17 axis and the role of resident T cells at entheseal sites, with evidence also implicating intestinal dysbiosis and gut barrier dysfunction in disease initiation. Clinically, the disease manifests with inflammatory back pain, peripheral arthritis, enthesitis, and various extra-articular features, including uveitis, psoriasis, and inflammatory bowel disease. MRI has significantly improved the early detection of sacroiliitis, offering higher sensitivity over conventional radiography. Current treatment strategies emphasize early use of nonsteroidal anti-inflammatory drugs (NSAIDs), tumor necrosis factor (TNF) inhibitors, and interleukin-17 (IL-17) blockers, which have demonstrated efficacy in halting disease progression and improving quality of life. A multidisciplinary approach that includes pharmacologic, rehabilitative, and psychosocial care is essential for comprehensive management.