Cardiovascular diseases like coronary heart disease and stroke are leading causes of death in the US. The main underlying cause is atherosclerosis, where arteries become thickened and narrowed due to plaque buildup over time. Risk factors for atherosclerosis and related conditions like hypertension include age, family history, obesity, smoking, diabetes, and diet. Treatment focuses on lifestyle changes like following the DASH diet, increasing physical activity, weight control, and managing conditions through medications and medical care when needed.