Rheumatoid arthritis (RA) is often characterized by the burden of swollen joints, pain, and de- creased physical function, but less understood are the many manifestations of additional health conditions that are associated with RA and its treatments. First brought to light with observations of increased mortality in RA, studies noted the increased rates of cardiovascular and infection events. The chronic, debilitating, autoimmune nature of RA affects the patient directly or indi rectly in almost all organ systems, from cardiovascular problems and infections to depression and gastrointestinal ulcers. On average, the established RA patient has two or more comorbid conditions. It should be the responsibility of the rheumatologist to take these and the risk of additional conditions into account when treating the patient. This chapter reviews important comorbidities in patients with RA, their prevalence, and their relation to RA.

Key words: anti-TNF therapy; cardiovascular disease; comorbid condition; comorbidity index; comorbidity; infection; malignancy; outcomes; rheumatoid arthritis.