Inclusion Criteria:  Clinical diagnosis of Radiographic Axial Spondylarthritis (r-axSpA) and meeting the modified New York Criteria for r-axSpA. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) score ≥ 4 at Baseline. Total back pain score ≥ 4 at Baseline. Inadequate response to at least two nonsteroidal anti-inflammatory drugs (NSAIDs) over an at least 4-week period in total at maximum recommended or tolerated doses, or participant has an intolerance to contraindication for NSAIDs as defined by the investigator. Upadacitinib prescribed in accordance with the applicable approved label and local regulatory and reimbursement policies.  Exclusion Criteria:  Prior exposure to any Janus kinase (JAK) inhibitor. Participants demonstrating active symptoms of fibromyalgia as per clinical diagnosis. Participation in a clinical trial of an investigational drug, concurrently or within the last 30 days. Unwillingness or inability to comply with the study requirements, including completion of patient reported outcome questionnaires. Participants who cannot be treated with upadacitinib according to the applicable approved label (e.g., contraindications). Vulnerable or protected adult patients with lack of capability to give informed consent.