Cardiology is the branch of medicine that deals with the study, diagnosis, and treatment of disorders of the heart and the circulatory system. It is a specialized field within internal medicine, and medical professionals who specialize in cardiology are known as cardiologists.

Cardiologists focus on the prevention, diagnosis, and treatment of conditions such as coronary artery disease, heart failure, valvular heart diseases, and congenital heart defects. They use a variety of diagnostic tools, including electrocardiograms (ECGs or EKGs), echocardiograms, and cardiac catheterization, to assess the structure and function of the heart.

Cardiologists may also be involved in procedures such as angioplasty and stent placement to address blockages in the blood vessels.