Cardiologists are doctors who specialize in diagnosing and treating diseases or conditions of the heart and blood vessels the cardiovascular system. You might also visit a cardiologist so you can learn about your risk factors for heart disease and find out what measures you can take for better heart health. Cardiology is a complex field, so many cardiologists specialize in different areas. All cardiologists are clinical cardiologists who focus on the diagnosis, medical management (use of medicines), and prevention of cardiovascular disease.