Cardiology is the medical specialty focused on diagnosing and treating disorders of the heart and circulatory system. Cardiologists manage conditions such as coronary artery disease, heart failure, arrhythmias, hypertension, and congenital heart defects. They use diagnostic tools like echocardiography and cardiac catheterization, along with treatments including medications, lifestyle modifications, and procedures like angioplasty and cardiac surgery, to improve heart health and prevent cardiovascular events.