Metabolic syndrome diagnostic criteria include at least three of five of the following medical conditions: abdominal obesity, high blood pressure, abnormal high fasting plasma glucose, elevated serum triglycerides and low HDL (high-density cholesterol) level. Sedentary, overweight and obesity are characteristically associated with the syndrome, nevertheless there are new studies which indicate that chronic stress, through deregulation of the hypothalamic-pituitary-adrenal (HPA) axis is also involved in the development of the syndrome. Metabolic syndrome represents a significant risk for the development of the cardiovascular diseases. New studies in the USA have estimated its prevalence at approximately 34% of the adult population and its prevalence is increasing with age. Diagnosis guidelines are establishing the metabolic syndrome diagnostic when are met three of the following five conditions: fasting glucose > or = 100 mg/dL or type 2 diabetes receiving drug therapy for hyperglycemia; high blood pressure > or = 130/85 mm Hg or high blood pressure receiving drug therapy; triglycerides > or =150 mg/dL or treatment for plasma hyper-triglyceride value; HDL-C < 40 mg/dL in men and < 50 mg/dL in women or if under therapy for reduced HDL-C levels and waist circumference of > or = 102 cm in men and > or = 88 cm in women. Besides important change of lifestyle, often drug therapy is needed (diuretics and ACE inhibitors, cholesterol drugs and weight loss medications). The value of physical activity and diet in prevention and treatment of the syndrome is supported by numerous studies. Association of metabolic syndrome and cardiovascular risk is still a matter of controversy, in what concerns the lack of significant cardiovascular risk in the case of obesity itself without metabolic syndrome.