This review is intended as an update on modern trends in the global impact and epidemiology of human immunodeficiency virus infection for physicians who are not acquired immunodeficiency syndrome experts. Africa has been the most affected, but epidemics are spreading in Asia and Russia. Therefore, physicians should be informed about seroconversion disease and human immunodeficiency virus diagnosis as well as the impact of sexually transmitted infections on many stages of human immunodeficiency virus. International treatment guidelines are available. Highly active antiretroviral therapy has been the mainstream therapy since 1996, but all drugs--regardless of class used--have potent side effects, many of which are dermatologic. Others affect the neurologic, hematopoietic, cerebral, and abdominal systems, and drug interactions are common. Lipodystrophy is a common, long-term side effect that is still not well understood. Broader use of highly active antiretroviral therapy has highlighted viral resistance. This is reviewed, and a simple explanation of therapeutic monitoring is provided.