In this module, we will discuss how to approach a patient presenting with polyarticular pain and some causes that you cannot afford to miss. Critical questions to ask your patient, including morning stiffness, distribution of joints involved, and characteristics of the pain will be reviewed, as will physical findings, which include pattern of joint involvement and dermatological findings indicative of vasculitis. Lastly, you will learn a comprehensive diagnostic approach to and management of some conditions causing polyarticular pain, such as rheumatoid arthritis, lupus arthritis, and granulomatosis with polyangiitis.