Rheumatologic diseases are commonly encountered in rehabilitation practice, in both inpatient and outpatient (ambulatory) settings. These diseases are diffuse and multifactorial. Most are poorly understood. In some diseases, such as rheumatoid arthritis and fibromyalgia, patients present with vague initial symptoms of fatigue and morning stiffness that can progress to a chronic debilitating process. In others, such as giant cell arteritis, immediate diagnosis and treatment is required to prevent disastrous consequences. Most rheumatologic diseases have limited treatment options, some of which (eg, glucocorticosteroids) have significant side effects.