The metabolic syndrome is a compilation of factors characterized by insulin resistance and the identification of 3 of the 5 criteria of abdominal obesity, elevated triglycerides, decreased high-density lipoprotein (HDL) level, elevated blood pressure, and elevated fasting plasma glucose. According to census data from 2000, these criteria have lead to the diagnosis of approximately 47 million Americans with the metabolic syndrome, correlating with the 61% increase in the incidence of obesity between 1991 and 2000. Insulin resistance occurs when target tissues cannot respond properly to normal concentrations of insulin. The results are hypercoagulability, endothelial dysfunction, inflammation, and eventually coronary artery disease. Treatment involves lifestyle modification, including diet and exercise, to treat obesity and prevent the development of diabetes. Patients who meet the criteria for the metabolic syndrome may also be treated with insulin-sparing and insulin-sensitizing medications that help to improve endothelial function, vascular reactivity, and vascular inflammation. Ultimately, treatment goals are to prevent cardiovascular disease by both altering the risk factors that are components of the syndrome, and treating the lifestyle issues inherent to the disease process, such as caloric restriction and increased physical activity. There are 2 million more women than men in the United States categorized as being obese, with the trend of obesity and diabetes increasing. In the last decade there has been a 74% increase in obesity, mostly in women. This epidemic needs to be understood and managed to prevent further morbidity and mortality owing to diabetes and cardiovascular disease.