What is the name for a doctor who specializes in treating the heart?

A doctor who specializes in treating the heart is called a cardiologist.

Cardiologists are physicians trained to diagnose and manage diseases of the heart and circulatory system. They commonly treat conditions such as coronary artery disease, heart failure, arrhythmias, heart-valve disorders, and high blood pressure. Their work may include physical examinations, electrocardiograms, echocardiograms, stress tests, and cardiac imaging.

Cardiology includes several subspecialties. Interventional cardiologists use catheter-based procedures to open narrowed arteries or treat structural problems, while electrophysiologists focus on abnormal heart rhythms. Cardiothoracic surgeons also treat the heart, but they are surgeons rather than cardiologists and perform operations such as bypass surgery or valve replacement.

The word cardiologist is built from cardio-, meaning heart, and -logist, referring to a specialist or practitioner in a field of study. The other options belong to different specialties: oncologists treat cancer, nephrologists treat kidney disease, and neurologists treat disorders of the nervous system. A primary-care doctor may identify a concern and refer a patient to a cardiologist.