During the evaluation of older adults with musculoskeletal complaints, it is necessary to differentiate periarticular conditions from intraarticular or arthritic conditions. It also is useful to classify the symptoms as acute or chronic and as mono-, oligo-, or polyarticular. Close attention should be paid to the history and physical exam findings, while laboratory tests and radiographs should only be used as supporting evidence of a clinical diagnosis. A search for the presence of joint inflammation is particularly important in the diagnostic process. Urgent evaluation is necessary in a patient with an acutely warm and swollen joint to rule out the presence of infection.