Because at least 10% of a primary care practice involves the evaluation of musculoskeletal disorders, internists must have a good foundation in musculoskeletal assessment. The is all the more necessary when the physician has many physically active patients. Active patients include those who regularly participate in a sport or exercise routine and those who engage in frequent physical activity that is not strictly organized or scheduled. Therefore, active patients not only include the high school cross-country rummer, the college football player, the teacher who jogs every morning, and the real-estate agent who goes to the gym five days a week, but also the construction worker and the accountant who plays softball every weekend. Although Sports Medicine naturally focuses on the many musculoskeletal injuries commonly seen in the office or clinic, other essential topics are also reviewed. These include nutrition, the pre-participation screening examination, cardiovascular conditions, infectious and gastrointestinal diseases, exercise-induced asthma, hypertension, drugs and supplements, and psychological issues.