Syndrome X is an older name for what is now usually called metabolic syndrome — a cluster of conditions that together sharply raise the risk of heart disease, stroke, and type 2 diabetes. The cluster includes abdominal obesity, high blood pressure, raised blood sugar, high triglycerides, and low HDL cholesterol; a diagnosis typically requires three or more. Insulin resistance is the common thread linking them. The term Syndrome X was coined to capture the idea that these risk factors travel together and share a root cause rather than coinciding by chance. Management is lifestyle-first: weight loss, physical activity, and dietary change, with medicines for the individual components as needed.